Well that’s between you and he, but that looks like a standard approach that usually works…
the only thing I’d add is to open that sigil - gaze at it in a meditative state until it starts to flash or look 3D, or lines start to disappear and reappear.
The drawing of it is part of that - helps to charge it with intention, then when you gaze on it and it’s open the link is made - at that point he’s “picked up the phone” on the other end and you can read out your petition so he’ll hear it. Hopefully you will be able to subtly feel him around - maybe behind you, maybe as a kenning.
Now, I’m very much NOT a demonolator - Demonolatry is a religion and I’m allergic to those - I think, the daemons actively don’t want worship or prayer - it’s disempowering for you, to give yourself away like that and beg for favours, while they’re busy trying to get you to take your power back from mainstream religious control and use it - to pray is (imo, obvs) to replace one slavemaster for another and work against everything an adversarial entity stands for. At best it assumptively puts an entity in a position is didn’t ask to be in.
I recommend instead establishing a mutually respectful alliance that will build into a friendship, a friendship between kings in thier respective realms. I like to think of it as my inviting a state visit from the dignitary of a neighbouring province, manners and decorum are observed and everybody is happy.
You don’t need any food offering - the evocation itself IS the offering - you are giving your time and energy, and that’s the best offering there is.