For example this is your api
https://www.googleapis.com/youtube/v3/playlists?part=snippet,contentDetails&channelId=UCrA&maxResults=50&key=AIZsk
Here with this api you will get result like
{
"kind": "youtube#playlistListResponse",
"etag": "\"XpPGQXPLgenD_n8JR4Qk/05DoUs3OS-AxnDI1FJbdM\"",
"nextPageToken": "CDIQAA",
"pageInfo": {
"totalResults": 585,
"resultsPerPage": 50
},
"items": [
{
"kind": "youtube#playlist",
"etag": "\"XpPGQXPLgenD_n8JR4Qk/7m0ztlwxvPmRtXjs\"",
.........
.........
In this result see "nextPageToken": "CDIQAA",
Now add pageToken parameter to your api
EX:
https://www.googleapis.com/youtube/v3/playlists?part=snippet,contentDetails&channelId=UCqrA&maxResults=50&key=AIZsk&pageToken=CDIQAA
Now this is your result, you will get nextPageToken and prevPageToken
{
"kind": "youtube#playlistListResponse",
"etag": "\"XpPGQX4Qk/R3A6jpxuE\"",
"nextPageToken": "CGQQAA",
"prevPageToken": "CDIQAQ",
"pageInfo": {
"totalResults": 585,
"resultsPerPage": 50
},
"items": [
{
"kind": "youtube#playlist",
"etag": "\"XpPGQXR4Qk/XsatNRtxJQ\"",
.........
.........