Concurrent user work management using GIT in Katalon

We have integrated Katalon with GIT wherein we have Master and developing branch.


Simultaneously , there are two users who are working on same project.
So if user A has committed the changes and user B does a pull request , there is a conflict and unable to complete the pull request.
Attaching the screenshot for the same.

https://git-scm.com/book/en/v2/Git-Branching-Rebasing