Issue
When I go to mydomain.example:8080
there is no authorization mechanism by default. I have had look at the configuration area but cannot find anywhere to add a basic username and password
Solution
Go to Manage Jenkins > Configure Global Security and select the Enable Security checkbox.
For the basic username/password authentication, I would recommend selecting Jenkins Own User Database for the security realm and then selecting Logged in Users can do anything or a matrix based strategy (in case when you have multiple users with different permissions) for the Authorization.
Answered By - CIGuy
Answer Checked By - Marie Seifert (JavaFixing Admin)