If your email address is incorrect, check what email address you have used to sign up and make sure to log in using that one.
If your password is not working, check if you did not accidentally copy a blank space behind it. If you cannot find your password, check your spam/junk folder. If you can also not find it there, whitelist firstname.lastname@example.org, request a new password, and check your inbox and spam folder again.
If you still have issues, contact email@example.com.