Asking for tips on take-out orders is total BS and everyone's doing it now. Sorry I'm not rewarding you for a product I haven't even tried yet.
Call it a 'delivery bid' and make it clear that if you don't bid enough, your order may be significantly delayed, cold, damaged or improperly handled, if delivered at all. Of course Doordash et al don't want to do that because the optics are pretty frakking bad.