Need to implemante a PHP fonction into my Joomla

For a Streaming plateform that we are making, we need to implemante a PHP fonction from our hosting provider to accept client to play the stream with a code. Also I would like to know how to do it for futur time.

Link: https://www.infomaniak.com/en/support/faq/2273/video-streaming-protecting-your-video-streams-with-a-unique-hash-code-token