You may need to resend invites to employees for example if they lost the original email.
Managers, owners and admins can resend invites for all pending staff here.
Alternatively, do this in the "Personnel" tab.
This is done simply by finding the "Pending" employee and clicking the blue "Resend invite" (as below):
You will get a green banner at the top of your screen if this is successful. For example:
If this email was not sent, your account may be in "Setup Mode".
Re-send invites only works for "Pending" employees who are yet to accept their invitation and sign-in for the first time.
For non-pending employees, try: reset their password.