When creating your Revv account, you created an account with an email and password. You will need both of these in order to sign in to your Revv account.
To sign in to your account, head to app.revv.co, your screen will look like this:
Enter your email and password that you used to create your account and click "Sign In."
Afterwards you will be redirected to your Revv account.
Note: If you can't remember your password or email associated with your account, please see instructions here on how to reset your password.
Don't have an account yet? Sign up here! https://app.revv.co/signup