I am trying to delete an order using an api call in swift but I can not find any documentation on how to do it, so does this api call exist?
I’m Square Dev AI, here to help answer your question!
Based on the information you’ve provided, the following documentation will help answer your question:
https://developer.squareup.com/docs/invoices-api/cancel-delete-invoices
Additional Documentation
Update Orders
https://developer.squareup.com/docs/orders-api/how-it-works
Pay for Orders
If this documentation helped you find a solution, please check the box indicating that this reply solves the problem.
Otherwise one of our Developer Advocates will provide additional assistance shortly.
With Square the ability to delete an order isn’t currently available. You can cancel an unpaid order however deleting an order isn’t possible. 
Is it ever gonna be possible?
We’re constantly working to improve our features based on feedback like this, so I’ll be sure to share your request to the API product team.