You don't specify who will be collecting the payment from the final customer. That is, is your customer the final customer, or is your customer the restaurant?

I have ordered food through online order/delivery services. All the ones I used received payment from me, then paid the restaurant. I don't know how the restaurants were paid. (Also, the services I used were "batch oriented". They would accept orders from customers in their service area until 10 am local time, consolidate orders for each restaurant, submit 1 large order to each restaurant, pick up from the restaurants and deliver to the office lobbies of the customers.)

Update: I strongly suspect the restaurants expected their payments when the (batched) orders were sent to them.

Years ago, I wrote an e-commerce web application that used Authorize.Net for payment processing. They supplied sample code in several languages, including Perl. I adapted their Perl code to my application, which then was able to accept credit/debit card payments, receive immediate confirmation, then update the customer's subscription status. Purchase of resources from our suppliers was handled externally to the web application.

(While the company was nice to work for and the work a reasonable challenge, I was quite happy to return the embedded control system industry when that market started to come back as the .com bubble burst (lucky timing for me))

If you are providing a food delivery service, such that you are charging the restaurant, then you probably will wind up doing this the old-fashioned way:   you’ll send the restaurant an itemized invoice once a month (or at some agreed-upon interval) and wait to be paid.

You should consult with your attorney, your accountant, and your business advisors, all of whom I presume that you have on-call.   The financial arrangement must be clear to all, and written into every (attorney-written!) contract.

The delivery of food is a complex undertaking with many regulatory implications meant to safeguard the public health (in any country).   It is quite ordinary to expect that the restaurant would not wish for you to have your money until after the food has been delivered and your mutual customer is satisfied.   (Every now and then, your delivery person will deliver to a smiling customer ... a real one, actually ... with a stopwatch and a temperature probe in his hand.)   I’m therefore quite sure that they will oblige you to send them an invoice in keeping with whatever is their corporate (nationwide?) policy.   C’est la guerre.

Yes, “split payment” protocols are available ... from every online payment processor, and even from your bank.   PayPal has no exclusive on this basic ACH (Automated Clearing-House) activity.   But you must not assume that this option will be available to your fledgling business.   Don’t implement your software, or, plan your business venture, until you are certain on this point.   (Your biggest, sustaining clients are quite likely to be very large corporations.)