You've asked about ordering an app in place of an entree on other threads. At the Disney owned restaurants (like Sanaa) they might be willing because they're not constrained by the reimbursement rules that affect the third party restaurants. You will have to ask at every restaurant and even if someone else was successful it is not a guarantee that you will be because Disney might change the rules for their restaurants or the manager on duty that evening might not allow it.
If a restaurant will not let you order an app instead of an entree, perhaps your parents can order the app as part of their DxDDP credit when you are dining together and ask that it be served at the same time as the entrees. In turn, you can use your credit to order an extra entree for your parents to make up for the app.
Or accept your parents generous offer of the DxDDP so you can order apps.