Only the Developer role has access to this page, where they can maintain their resources.
Click on Resources in the main menu:

You will only be able to view resources for the applications that you have developer access to.
You can filter and search using the utility bar:

If you have a YAML or JSON file already prepared, you can upload it directly on the resources listing page (see above):

or in the create a resource page.
Click on the edit icon (pencil) for a resource to view and edit it:

See create a resource for more details.
Note: You will only have permissions to edit a core resource if api.core_resource_lock is set to false in the ApiOpenStudio settings.yml file.
Click on the delete icon (trashcan) for a resource to delete it:

Confirm on the pop up modal:

Note: You will only have permissions to delete a core resource if api.core_resource_lock is set to false in the ApiOpenStudio settings.yml file.