This is the first time I have heard about the possibility of restricting the login to Trust Wallet. Trust Wallet can only do this by accessing the private key and preventing you from extracting the private key, which is something they claim does not happen. Therefore, the message that you received is a phishing message and often contains a link to download A fake wallet where they can access your coins.
Do not use Trust Wallet, it is closed source and there are some good alternatives.