Take a look at the referenced URL, you'll see the returned content is something like this

    a:1:{i:0;a:23:{s:2:"id";i:466939644;s:5:"title";s:17:"Cognifirm intro 3";s:11:"description";s:0:"";s:3:"url";s:27:"https://vimeo.com/466939644";s:11:"upload_date";s:19:"2020-10-10 16:14:03";s:15:"thumbnail_small";s:49:"https://i.vimeocdn.com/video/972928988_100x75.jpg";s:16:"thumbnail_medium";s:50:"https://i.vimeocdn.com/video/972928988_200x150.jpg";s:15:"thumbnail_large";s:46:"https://i.vimeocdn.com/video/972928988_640.jpg";s:7:"user_id";i:112487323;s:9:"user_name";s:12:"Per Damgaard";s:8:"user_url";s:31:"https://vimeo.com/user112487323";s:19:"user_portrait_small";s:55:"https://i.vimeocdn.com/portrait/defaults-blue_30x30.png";s:20:"user_portrait_medium";s:55:"https://i.vimeocdn.com/portrait/defaults-blue_75x75.png";s:19:"user_portrait_large";s:57:"https://i.vimeocdn.com/portrait/defaults-blue_100x100.png";s:18:"user_portrait_huge";s:57:"https://i.vimeocdn.com/portrait/defaults-blue_300x300.png";s:21:"stats_number_of_likes";i:0;s:21:"stats_number_of_plays";i:111;s:24:"stats_number_of_comments";i:0;s:8:"duration";i:109;s:5:"width";i:1920;s:6:"height";i:1080;s:4:"tags";s:0:"";s:13:"embed_privacy";s:8:"anywhere";}}

It's designed to be directly passed to unserialize($str) which is an incredibly dangerous thing to do with potentially unsafe input.

This is perhaps the strangest API design I've ever seen and these data could have easily been returned and parsed as JSON.