Chatex email sign-in uses a magic link that currently expires after 5 minutes.
Check these first
Open the newest email only. Older magic links can fail after you request another one.
Check spam, junk, promotions, and any alternate inbox you may have used.
Make sure you entered the correct email. If the account was created with Google, Apple, or Microsoft, use that provider instead of email sign-in.
If the link looks expired, request a fresh one and use it immediately.
If you are trying to recover a paid account and can no longer reach the right inbox, use the support page with your support code, likely account emails, or charge details.