I have the same error in Sourcetree app and after some changes (update git and Sourcetree app to latest version and delete AppData\Local\Atlassian\SourceTree\passwd) see this message when I want login.
remote: Bitbucket Cloud recently stopped supporting account passwords for Git authentication.
Good luck! Let me know if this works for you.
remote: See our community post for more details: https://atlassian.community/t5/x/x/ba-p/1948231
remote: App passwords are recommended for most use cases and can be created in your Personal settings:
remote: https://bitbucket.org/account/settings/app-passwords/
Create an app password
To create an app password:
From your avatar in the bottom left, click Personal Settings.
Click App passwords under Access management.
Click Create app password.
Give the app password a name related to the application that will
use the password.
Select the specific access and permissions you want this application
password to have.
Copy the generated password and either record or paste it into the
application you want to give access. The password is only displayed
this one time.
Add an app password to Sourcetree or another application
To add your app password to Sourcetree:
Go to the tab where you'll add or edit your account details:
(Windows) Go to Tools > Options. From the Options dialog, select the
Authentication tab.
(macOS) Go to Sourcetree > Preferences. From the dialog that
options, select the Accounts tab.
Click to Edit your account details or Add a new one.
From Authentication or Auth Type, select Basic and enter your
Username if it's not already there.
Enter the app password you just created as your Password. If you're
on Windows, you'll need to hit Refresh Password first.
Click OK or Save to save your account details.
To add your app password to another application, see the application's documentation for how to apply the app password.