Authentication failure

I having been getting authentication failure on my MT5 app whenever I want to logging to my accounts after reactivation. What could be the error?

Hi @annelid-addaxes-2, thank you for joining the community! You may refer to this article DMT5 Login Failed due to "Authentication Failed" - Server to seek more information on the issue you are facing. If you need further assistance, kindly reach out to us via LiveChat, for better assistance and protection of your account’s data. We’ll work with you to resolve any issues as quickly as possible.

I’m on the site but don’t know my navigation to conduct live chat. Assistance please