The tutorial json is only the example. You may also have an test in the following site.
https://mars.restgate.net/intro/en/suite_en_rakuten.html#cipher

1> Generate RSA Key

Generate a random Public and Private key pair of RSA.
https://acrosuite-cipher.p.rapidapi.com/v0_1/CstService/tools/cipher/rsakey
http method: get

Request Header parameters:

x-rapidapi-host: acrosuite-cipher.p.rapidapi.com
x-rapidapi-key: [your rapidapi-key]

Response JSON Example:

{
    "contents": {
        "publicKey": "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",
        "privateKey": "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"
    },
    "errors": null,
    "memo": "Congratulations on your success!",
    "result": true
}

2> Generate Digital Signature

Generate Digital Signature by RSA Key. You need prepare Public/Private Key above.
https://acrosuite-cipher.p.rapidapi.com/v0_1/CstService/tools/cipher/signature
http method: post

Request Header parameters:

Content-Type: application/json
x-rapidapi-host: acrosuite-cipher.p.rapidapi.com
x-rapidapi-key: [your rapidapi-key]

Request JSON Example:

 {
        "publicKey": "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",
        "privateKey": "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",
        "signName": "User2002_1"
 }

“publicKey” and “privateKey” are a key pair of RSA generated in 1>.
“signName” may be free to set as you like.

Response JSON Example:

-Successful case:

{
    "contents": {
        "publicKey": "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",
        "signature": "H4sIAAAAAAAAAAGbAGT/rO0ABXVyAAJbQqzzF/gGCFTgAgAAeHAAAACAffMkYs+gtId3YHPhK9WZSwQArMTGCqw6uS9f9iI1+iPkS5DNld06JAQTrhVTbhuoBtQkF7EfU2wj/X8fMBS7JpsL7A67jAHw/iH7+lhrwlIlqhCwTezWGi6CBFup9bPRPsexgmWpVvog2d1PAdY+6lmrlhlDlEGDxarO77sKqflogf+wmwAAAA==@@@@@@QIn3zjLAdfiRgSh+z6oZHgy0IAxzL46k",
        "signDT": "2021-10-23 10:58:29.319",
        "signHash": "y6MjZV879hupNRFtIixVVQ",
        "signName": "User2002_1"
    },
    "errors": null,
    "memo": "Congratulations on your success!",
    "result": true
}

“signature”: a secret string which encrypted “signName” and “signDT” by “privateKey” in 1>.

-Failed case:

{
    "contents": null,
    "errors": [
        {
            "code": "203",
            "message": "The staff doesn't exist!",
            "type": "NotFound"
        }
    ],
    "memo": "Unfortunately, you failed!",
    "result": false
}

3> Validate Digital Signature

Do Validity Check for Digital Signature by RSA.
https://acrosuite-cipher.p.rapidapi.com/v0_1/CstService/tools/cipher/isvalidsignature
http method: post

Request Header parameters:

Content-Type: application/json
x-rapidapi-host: acrosuite-cipher.p.rapidapi.com
x-rapidapi-key: [your rapidapi-key]

Request JSON Example:

 {
        "publicKey": "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",
        "signature": "H4sIAAAAAAAAAAGbAGT/rO0ABXVyAAJbQqzzF/gGCFTgAgAAeHAAAACAffMkYs+gtId3YHPhK9WZSwQArMTGCqw6uS9f9iI1+iPkS5DNld06JAQTrhVTbhuoBtQkF7EfU2wj/X8fMBS7JpsL7A67jAHw/iH7+lhrwlIlqhCwTezWGi6CBFup9bPRPsexgmWpVvog2d1PAdY+6lmrlhlDlEGDxarO77sKqflogf+wmwAAAA==@@@@@@QIn3zjLAdfiRgSh+z6oZHgy0IAxzL46k",
        "signDT": "2021-10-23 10:58:29.319",
        "signHash": "y6MjZV879hupNRFtIixVVQ",
        "signName": "User2002_1"
 }

Here, Request is “contents” from 2>.

Response JSON Example:

-Successful case:

{
    "contents": {
        "code": "0000",
        "message": "Congratulations on your success!",
        "subject": "checkSignature"
    },
    "errors": null,
    "memo": "",
    "result": true
}

-Failed case:

{
    "contents": null,
    "errors": [
        {
            "code": "650",
            "message": "The signature is invalid!",
            "type": "ParameterError"
        }
    ],
    "memo": "Unfortunately, you failed!",
    "result": false
}

“signature” will be decrypted by “publicKey”. if the decrypted result matches with “signName” and “signDT”, it means Signature is validate.

4> RSA Cipher/Decipher

Encrypt or Decrypt text messages by Public/Private Key of RSA.
https://acrosuite-cipher.p.rapidapi.com/v0_1/CstService/tools/cipher/message
http method: post
Generally, Encrypt by Public Key & Decrypt by Private Key or Encrypt by Private Key & Decrypt by Public Key is used as a Encrypt/Decrypt pair.

Request Header parameters:

x-rapidapi-host: acrosuite-cipher.p.rapidapi.com
x-rapidapi-key: [your rapidapi-key]

Encrypt case by Public Key

Request Query parameters:

cipherType=0
cipherType: 0:cipher, 1:decipher

Request JSON Example:

{
    "cipherKey": "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",
    "keyType": 0,
    "message": "123456"
}

“cipherKey”: Public Key or Private Key in advance. Here, “publicKey” genarated in 1>. is used.
“keyType”: 0:PublicKey; 1:PrivateKey
"message": plain text which will be encrypted.

Response JSON Example:

{
    "contents": {
        "message": "H4sIAAAAAAAAAAGbAGT/rO0ABXVyAAJbQqzzF/gGCFTgAgAAeHAAAACANZe11wx9sD7O1fOisv8zx5QLdsB6hGSana6rI2fI2gQm4J4I2cVbALh7DcRRmLc/iFYnAeV0VL09o1UkPaNrL3BecxyHaf9llkt5vTW3UHwvHTCF2VCFK88bqW/SfQs1CAstEtvNLO8+qev4FOUQdyw6v//W6LPbqIVjiYRfWhTGTtQDmwAAAA==@@@@@@YF4d6glOIsM="
    },
    "errors": null,
    "memo": "",
    "result": true
}

“contents”.“message”: the secret text encrypted by “publicKey” above.

Decrypt case by Private Key

Request Query parameters:

cipherType=1
cipherType: 0:cipher, 1:decipher

Request JSON Example:

{
    "cipherKey": "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",
    "keyType": 1,
    "message": "H4sIAAAAAAAAAAGbAGT/rO0ABXVyAAJbQqzzF/gGCFTgAgAAeHAAAACANZe11wx9sD7O1fOisv8zx5QLdsB6hGSana6rI2fI2gQm4J4I2cVbALh7DcRRmLc/iFYnAeV0VL09o1UkPaNrL3BecxyHaf9llkt5vTW3UHwvHTCF2VCFK88bqW/SfQs1CAstEtvNLO8+qev4FOUQdyw6v//W6LPbqIVjiYRfWhTGTtQDmwAAAA==@@@@@@YF4d6glOIsM="
}

“cipherKey”: Public Key or Private Key in advance. Here, “privateKey” genarated in 1>. is used.
“keyType”: 0:PublicKey; 1:PrivateKey
"message": secret text which will be decrypted.

Response JSON Example:

{
    "contents": {
        "message": "123456"
    },
    "errors": null,
    "memo": "",
    "result": true
}

“contents”.“message”: the plain text decrypted by “privateKey” above.

On the contrary, Encrypt case by Public Key & Decrypt case by Private Key may be also used.