I have designed the app, and it has not been published yet. Now, I want to use the external user signup and login option. However, I could not figure out how to use this for the existing app because It is possible to choose this option when first create the app, there is an “Advanced Options” section, and this option can choose it for this external user from there. (attached the screenshot) However, I don’t know how to apply this option to the existing app.
Thanks in advance