Thanks for reaching out Peter,
Edge seems to be asking for the primary password you made for its password manager, not your Microsoft account password. If the password you enter does not work, it may have been changed.
The easiest fix is to reset it, but this will remove all saved passwords from the manager. To reset, open Edge and go to Settings > Profiles > Passwords. Look for the Primary Password option and a Forgot password or Reset link to create a new password.
Before you reset, are you signed into Edge with your Microsoft account and is sync on? This helps to know if your saved passwords can be restored after the reset.
Best,
Rez