There are multiple ways to sign in to Accointing.com or the Accointing App.
You can only change your password through Accointing if you do not sign-in with Google or Apple
If you sign-in using the email address and password fields, click on Sign In and then Forgot Password in the pop-up.
You will receive an email to your inbox with a link to change your email.
Clicking on that link will take you to a new page where you can set and confirm your new password.