You are trying to signin to Authy (https://dashboard.authy.com/signin), you receive the message:

User not found

or

Wrong email or password

The dashboard (https://dashboard.authy.com/signin) is for Authy Application managers and developers only. If you are a normal user and just want to access your account, you will not have an account in the Authy dashboard.

We currently do not provide a website for normal users to manage their account, instead, users can use the free Authy app for mobile or desktop.