REGISTER or login:
It appears that creating a user in iNav doesn't provide a way to specify that option. I suggest submitting a request to IBM at their Design change request for IBM i and related software page. The more requests for it, the more likely it will be done, so others should also enter similar requests. But also, when work is done on one request, some othe request is being set aside.
For this request, you might review all possible user profile attributes. Ask for every attribute that ought to be there. It'll be easier doing them at one time.
And keep the page address handy. Make requests in the future for anything you think is needed. It's how IBM knows what to do. Let others know about the page and about requests that you want.