You can reset your own password from the sign-in page — no one needs to do it for you.
Steps
On the sign-in page, click Forget Password? under the password box.
Enter the email address you sign in with, and click Submit.
You will see Check your email. Open the reset link we send.
Choose a new password. It must be at least 8 characters and include numbers.
Sign in with the new password.
The Forget Password screen, asking for the email address to send a reset link to
If the email doesn't arrive
Check the spam folder — it is the most common answer.
Check the address. The reset only goes to an email that already has an account. A typo, or a different address from the one you were invited with, produces no email.
Check you are on the right workspace. Each workspace has its own address, like northwind.atwork.so. Resetting on the wrong one will not help you into yours.
Never accepted your invite? Then there is no password to reset yet — ask whoever invited you to resend the invitation.
Signed in with Google?
If you use Continue with Google, you do not have an Atwork password at all. Reset it with Google instead, and keep using that button.