How to check if a user is the owner of the site?

Hello everyone, any time of the day!
Could you please advise on how to implement or create the following?
I need certain users who have verified their website to have access to specific functions, fields in node forms, or something along those lines.
I'm particularly interested in how to verify if a user is the owner of a website. Something similar to when a site is added for indexing in Google...
Are there any ready-made solutions in the form of a module or something else?
I'm not very familiar with PHP. I know very little, so I don't think I can write a module myself.
I would be very, very grateful in advance for any help or guidance on which direction to take!