How to resolve 'incorrect password' and 'unknown error' when logging into Instagram on iPhone?

On the iPhone, when entering the password in the Instagram application, it says that the password is incorrect. I changed the password several times, when asking for a link to log in, it says "unknown error" It logs in through Safari without any problems, I reinstalled the application several times, tried VPN, even updated iOS and all without result

[Re-Titled by Moderator]