Hi @ghteotonio! As you are new to the community, when you get a chance, please introduce yourself here.
You will need to set up a table administrator user, like you did with the sample user in your server setup, but giving them enough admin. permissions to be able to reset the tables (see: Data Permission Filters — ODK-X Docs). You may also be able to use the admin account you used in setting up your server.
Alternatively, you can use ODK-X suitcase to reset the server: ODK-X Suitcase — ODK-X Docs