Hi @Nigel_Mendoza,
You can most definitely do this. I currently have an app for affiliates but it is public with login. To prevent anyone who happens across the app to signup and see private pages I do this exact thing.
- In your user sheet create a column for their code and a column for a validation flag.
- base the visibility of all private tabs on the validation flag of each user (assign the email column as row owner in the user sheet)
- create a page where the users can input their codes (either an editable field or a form, if using a form, more work will be required to extract/validate the code, so I prefer to use a user input text field linked directly to the code column)
- you should have a list of valid codes somewhere in the sheet to compare to the submitted codes
- if the code is valid the validation cell should change to true exposing all the private sheets (a simple formula in sheets or lookup in the data editor should do)
- to “lock in” the code you can also disable/hide the code entry page (or component) using the validation flag in reverse (hide if valid)
Please let me know if the above helps, or if you have any further questions!