How to make merge new changes to github? (already published one version in app VTEX store)
Could you be more specific in your question?
Is your idea to publish an app/theme and add it to the final (production) environment?
You can look at these two documentations:
Update an existing app in the store, we’ve already got a github repository version and I tried to make new branch and pull it to the github, it says you have no write access.