What is a best way to sync files from `develop` to `master`?

I need to move my files from the develop environment into master.

Could you be more specific when you talk about these files?
Do you mean, source file?
We use git. Therefore, you can use either git rebase or git merge:
https://git-scm.com/docs/git-rebase
https://git-scm.com/docs/git-merge

Several helpful tutorials explain both:
https://medium.com/datadriveninvestor/git-rebase-vs-merge-cc5199edd77c
https://www.atlassian.com/git/tutorials/merging-vs-rebasing

The choose is more oriented to your business; there is the right way on the situation.