once it has been clicked, you get on another site on which you see your btc-address AND your balance.
I can do that. What will the other site be?
Sorry, that was my lack of english skills... it wouldn't be another site, but just another page. Or frame....
So first, a user gets on a site where he can either log in or register.
All that is mandatory for registering is the e-mail address. He then gets a password.
With the e-mail address and the password, the user then can log in.
Upon registration, he gets a wallet address.
When logged in, the user sees his wallet address and his balance.
In a further step, but this would be the next part of the project, he would be able to deposit or withdraw, but only with 2FA.
Sorry for being unclear in the first description. Hope these further details help to understand what it should be able to do.