Charge for consultation in the GPT store

I’ve seen that they sync to an external page with the ChatGPT account, and then I see that they charge for consultations by paying on that external page. ¿How do they do it?

I’ve seen that they sync to an external page with the ChatGPT account

You mean the builder profile link? That’s what you set when you create a custom GPT, anyone (maybe requires a Plus account) can do that.

I am talking about this chat GPT ‘Photo Realistic GPT’ (genigpt), You can make free inquiries there, but after a few uses, it asks you to pay to continue using it through another website.