How do you make a subscription page?

I want to make a subscription page like YouTube, in which after purchasing it gives the features of it

Use an in app billing extension
There are currently 3 extensions available
You can find them after doing a search in the community or in the extensions directory


SEE , what I want you not understand, I want to know if a person get the subscription then how will he. Get the benefits of it

better to store the data in a relation database like MySQL.

Hey I don't know how to do it becz I'm beginner so can you pls send some tutorial videos for that