Per the following Microsoft Doc, it appears that a user who is licensed for Project for the Web/Project Online has the ability to create a resource when managing a project. However, if they need a resource edited/deleted that he/she originally created, it appears they would also need a Dynamics 365 license or would have to reach out to a D365 admin. If a project manager has the ability to create a resource, they should also have the ability to edit or delete a resource they created.

https://docs.microsoft.com/en-us/project-for-the-web/create-nonuser-resources-in-project-for-the-web