This solution worked for me on the macOS. Thanks.
@hebbex said in "Confirm your identity to enable encryption" button not working:

Hi there pals. I've see a solution in another topic. And I tried. It worked for me. I hope it will works you for aswell

"Test this solution. Remove the Opera Safe Store password from Keychain Access login item.

Steps:

Open Keychain Access application

Choose 'login' keychain on left

Choose 'Password' group

Find 'Opera Safe Storage' entry, right click it and choose Delete."