Is the profile open for editing? Have you found the parents both on Wikitree? Do you have a reliable source for the parents?
If yes, you can Edit the Profile, select the Add Mother or Add Father, enter the wikitree ID at the top, 'scroll' to the bottom to see the the other parent is listed with a checkmark. If so, select the Save and that should add both parents to the profile. Then, add a source to the profiles.