Computer Configuration > Administrative Templates > Microsoft Edge - Default Settings (users can override) > Password manager and protection
Both
HKLM\Software\Policies\Microsoft\Edge\Recommended
Lets you configure the default display of the browser password reveal button for password input fields on websites. If you enable or don't configure this policy, the browser user setting defaults to displaying the password reveal button. If you disable this policy, the browser user setting won't display the password reveal button. For accessibility, users can change the browser setting from the default policy. This policy only affects the browser password reveal button, it doesn't affect websites' custom reveal buttons.