Since you did not name the client, no one is going to guess what the requirements are.
Some of the scenarios I am familiar with only allow ordering via the required App. Orhers clearly state "online, via website or App." None allow ordering any other way. Most have additional instructions; as to how many attempts (3 in most scenarios) and if a phone call is required to determine if the location is aware of any issues using the website or App.
As you can see, if you have not read the requirements then you should not attempt to perform the shop.
My posts are solely based on my opinions and for my entertainment, contact a professional if you need real advice.
When you get in debt you become a slave. - Andrew Jackson