I have trouble accessing my master branch

What happens?
I’m ready to do my first commit but I can’t access the branch that I created in the repo.
I do not know if it is because my user is not added in the policy to which I belong that is the junior or that I can not enter my name and email to the .mailmap.

The description of what happens
I can’t access the branch I created in the repo.
Evidence 1

Did you try any workaround? What did you do?
Regarding the file . mailmap and that my user does not appear in the policy, I asked in the forum about it and I have not received a response.
Evidence 2

Evidence 1

Evidence 2

** I need help with**
please ask for help to solve the problems mentioned in the body of the message/forum in order to perform my commit

You cannot access that branch if you have not previously created it.