If a user in your workspace forgets their password, they can reset it in one of two ways. They can either use the forgot password feature of the login screen (see Setting or Resetting Your Password), or they can ask a user admin (you) to send them a new Welcome Email like the one they received when they first signed up.
To do this, click on Users in the left-hand sidebar to access the user list:
On the user list, locate the relevant user and click on them:
Finally, click Resend Welcome Email to send them a new welcome email containing a new password reset link: