SHELL

error: src refspec master does not match any. git

# You are trying to add an empty repository, add something first, like a readme
touch README.md
git add README.md
git commit -m "Initial commit"
git push --set-upstream origin master

error: src refspec main does not match any

git merge --allow-unrelated-histories origin/main

error: src refspec main does not match any

"main" is the usual branch name in Github repos. In some repos, it can be master or some other name
use the following command at that time
git push origin master