There are 2 ways you can try:

First, you can try the “remote edit” tool, so 2 of you can work on the same project, similar to Google Doc: https://forum.creaticode.com/topic/1869/remote-edit-multiple-users-working-on-the-same-project-remotely

Second, you can try to click “Share” and then “Share with writing permission”, then specify the password and give that to your friend.