The My Personal Credentials feature is a single credential entry which is locally stored on your device in your profile.
If you can't use integrated security then you must store your credentials in My Personal Credentials.
This allows you to centralize one special credential to replace or emulate the ones for your session. When a password change is needed you simply need to change it once in My Personal Credentials.
Select a credential type to use as your Personal Credentials and then enter the username and password.
In your session, select My personal credentials in the Credentials field.