At Mailgun.com, there is no page where you can copy or get the password of your smtp credentials. The SMTP password is not visible and can only be reset.
So, if you are trying to use your mailgun smtp settings somewhere and you don’t know the password of the existing smtp user you’ve created for your domain in mailgun, it’s either you create a new user to use or reset the existing user’s credentials.
If you create a new user, make sure to save the password somewhere, as you won’t be able to retrieve it again.
Your mailgun SMTP credentials are different for each domain you add. You can find your default credentials, and add more, by clicking through to your domain settings. at mailgun.com