When I want to jump start the starter, I used a spare car battery set on the ground a few feet away from the bike. With a good set of jumper cables hooked to the battery, I hook thr ground to a foot peg nut. Put a 4-5 inch bolt in the hot cable, turn on the key set the choke, touch the bolt to the solenoid/starter relay on the cable to the starter.This just sends the car battery power to the starter. The bikes battery powers the ignition. This protect the bike electrics.
On yours instead of hooking the ground cable to the bike put thr bolt in the ground clamp, hook the hot clamp to the cable on the starter. Now touch the bolt to a good ground. This should spin the starter just fine. If you don't have a cable on the starter I would put one on for this. Crawling on the ground to touch the bolt to the starter cable connection will be a real PITA.
Either way this gets any sparks away from the batteries.
Good luck on your initial start up and running.