https://dev.twitch.tv/docs/v5/guides/migration
Please also read the migration guide
Please also read the example request in the docs you linked
curl -H 'Accept: application/vnd.twitchtv.v5+json' \
-H 'Client-ID: uo6dggojyb8d6soh92zknwmi5ej1q2' \
-X GET 'https://api.twitch.tv/kraken/chat/emoticon_images?emotesets=19151'