What do you need userid to use User Posts. You can find it by using UserID end point in finding Userid.

You have to enter userid and count to get User Posts information.
After the first request, you need to send data from end_cursor to paginate.

== very important in pagination

The data you will send as a request:
userid: 25025320
count : 12

The data you will send as pagination:
userid: 25025320
count : 12
end_cursor: QVFCMHAycGRXNkpnVE9aX0tzc2J6QXBVT01aYzQxNVJaejctaE5OejBRRTIxbzBKejY4M2I0dGtLcjc1d2ZtUUxKSUREQlZ1ejlQWmFvUmNNima==