Oracle Developer Cloud Service comes with Git repository. If you want your SQL project integrated with you can achieve it as follows:
1- Open sqlDeveloper ans select a connection
2- Goto Team->Git->Clone
3- Clone a DevCS repository with the Clone Wizard. In one of the steps you inform the path where the repo will be cloned into
4- Go to the directory where the project was cloned into and add/create files inside it
5- Add selected/all files to the local git repo
6- Commit changes
7- Push local repo to remote git repo in DevCS
8- Verify changes in DevCS
Enjoy š
approaching off the bow 