In Overleaf each project has an owner. The owner is the only person who can assign permissions to the project and in whose account the project is stored.

In some cases, it may be necessary to transfer ownership of a document to another person (for example, when a researcher has created a document and leaves the project).

To do this, the owner must follow these steps:

1. Share it with editing permissions with the person to whom they want to transfer ownership.
2. Click the "Share" button again, and change the new owner's permissions from "Editor" to "Owner".

More information: Transferring project ownership.