There are two ways you can do this. The first is using a Constituent Registration Information (CRI) question:
  1. Create a question of type "Constituent Registration Information"
  2. On steps b and c, choose which basic profile fields you would like to be required and which ones to present to the user
  3. On step d, choose how you would like to update constituents in various scenarios (logged in vs. not logged in, etc.)
However, if there is a field you would like to update that is not available, here is a more general way to do this:
  1. Create a question of any type that could correspond to a profile field, such as short text value, T/F, numeric, etc.
  2. When editing the question, on step 6 check the option under "Constituent Profile Field Update" to "Select existing field"
  3. Select a field type and then a field. Note that "Additional Information" will pull up all custom fields.
These questions will update using whatever guidelines you defined in the CRI question. Note that a CRI question is required to update a constituent profile, as it allows Luminate to match constituents who are not logged in with their profile (if applicable).