Originally Posted by K3qH49d7k

On the contrary, NexusPHP sites often have a section for exchanging invitations

But you won't find the invitation exchange section anywhere because it's forbidden!
As you stated earlier.

Originally Posted by K3qH49d7k

Most active ptt, mteam, bts, ubits, soulvoice, icc2022, carpt. But I've gotten rarer ones on other sites as well, but the wait for a response can be over a month.

There are known and faster ways to get an invitation and you don't have to wait for months (of course I am not talking about buying !!!) everything legally.
Within an hour or two you have an invitation available in your mailbox.