As per the endpoints use the language codes as shown below for the respective languages.

Afrikaans=Afrikaans
Albanian=Albanian
Amharic=Amharic
Ancient-Greek-1453=Ancient-Greek-1453
arabic=arabic
Armenian=Armenian
Assamese=Assamese
azerbaijani=azerbaijani
basque=basque
Belarusian=Belarusian
bengali=bengali
Breton=Breton
Bulgarian=Bulgarian
Burmese=Burmese
Castilian=Castilian
catalan=catalan
Cebuano=Cebuano
chinese=chinese
Chinese-Traditional=Chinese-Traditional
Croatian=Croatian
Czech=Czech
danish=danish
dutch=dutch
english=english
Esperanto=Esperanto
Estonian=Estonian
Farsi=Farsi
Filipino=Filipino
finnish=finnish
Flemish=Flemish
french=french
Galician=Galician
Georgian=Georgian
german=german
greek=greek
Greek-Modern-1453=Greek-Modern-1453
Gujarati=Gujarati
Hausa=Hausa
hebrew=hebrew
Hebrew-Modern=Hebrew-Modern
Hindi=Hindi
hinglish=hinglish
hungarian=hungarian
Icelandic=Icelandic
indonesian=indonesian
Irish=Irish
italian=italian
Japanese=Japanese
Kannada=Kannada
kazakh=kazakh
Kirghiz=Kirghiz
Korean=Korean
Kurdish=Kurdish
Kyrgyz=Kyrgyz
Latin=Latin
Latvian=Latvian
Letzeburgesch=Letzeburgesch
Ligurian=Ligurian
Lithuanian=Lithuanian
Luxembourgish=Luxembourgish
Macedonian=Macedonian
Malay=Malay
Malayalam=Malayalam
Marathi=Marathi
Moldavian=Moldavian
Moldovan=Moldovan
Mongolian=Mongolian
nepali=nepali
norwegian=norwegian
Oriya=Oriya
Pashto=Pashto
Persian=Persian
Polish=Polish
portuguese=portuguese
Punjabi=Punjabi
romanian=romanian
russian=russian
Sanskrit=Sanskrit
Serbian=Serbian
Sesotho=Sesotho
Sinhala=Sinhala
Slovak=Slovak
slovene=slovene
Slovene=Slovene
Somali=Somali
Sotho=Sotho
spanish=spanish
Swahili=Swahili
swedish=swedish
Tagalog=Tagalog
tajik=tajik
Tamil=Tamil
Tatar=Tatar
Telugu=Telugu
Thai=Thai
Tigrinya=Tigrinya
Tswana=Tswana
turkish=turkish
Ukrainian=Ukrainian
Urdu=Urdu
Uzbek=Uzbek
Valencian=Valencian
Vietnamese=Vietnamese
Welsh=Welsh
Yoruba=Yoruba
Zulu=Zulu