On the web, iOS and Windows app sign in screens there is a Forgotten password? link. Once you enter your email address here, you'll get an email that you can use to email yourself a link for resetting your password.
If you're using an Android device, you'll need to go to APE Mobile on the web (use your server as the URL, usually something like [organization.apemobile.com] and request your password reset link.
Click the link in the email you receive (check your spam filter if you can't find it😏) to enter a new password.