Getting the same response despite adding pageToken to the request

I think it is due to = (equls) sign in myPageToken

https://youtube.googleapis.com/youtube/v3/comments?part=snippet&parentId=UgzEc5r9H9uF6eGzXsJ4AaABAg&key=<API_KEY>

and

https://youtube.googleapis.com/youtube/v3/comments?part=snippet&parentId=UgzEc5r9H9uF6eGzXsJ4AaABAg&pageToken=Z2V0X2NvbW1lbnRfd2l0aF9yZXBsaWVzX3N0cmVhbS0tQ2dnSWdBUVZGN2ZST0JJRkNLQWdHQUVZQUNJT0Nnd0l4YnJSc2dZUTROUzg1d0U%3D&key=<API_KEY>

is giving me same response

In 2nd request I added pageToken which is received form 1st request.

nextPageToken received from 1st request is :

Z2V0X2NvbW1lbnRfd2l0aF9yZXBsaWVzX3N0cmVhbS0tQ2dnSWdBUVZGN2ZST0JJRkNLQWdHQUVZQUNJT0Nnd0l4YnJSc2dZUTROUzg1d0U=

I am expecting different responses in both cases. But I am getting same responses.