I am facing an issue in login "Branch Not found"

Netlify CMS
,
#1

Here is My my yml file code.Please help me how to solve this i am new on Netlify.
backend:
name: git-gateway
branch: master

#2

Have you configured the repo name correctly?

It should be like this:

backend:
  branch: <branch-name>
  name: git-gateway
  repo: <repo-owner>/<repo-name>