If you want to enable other users to create or edit the experiment, their role on the project level has to be Owner or User.
Owner has the full authority when it comes to managing projects. This means he can edit, archive or restore a project and manage its users. The User has very similar rights as the Owner, however, they are not authorised to manage the project or the users, they will also be unable to archive any data.
To assign roles or grant permissions to other users, you have to be the Owner of the project. Select a project on your dashboard, click on the avatar icon and continue to Manage users. A window for managing users for this particular project will appear. Click on the first box to select a user and on the second one to select a role. Please note that the user has to be a team member, so that you can manage their privilege as well as role.