AFAIK, my trigger is a SPST momentary switch. It has no function to start gas ahead of energizing the wire. It's the same as my little Lincoln SP 120v unit that I started with.
One other thing to mention is power. Years ago I welded for a member here in an old garage that was fed by an ancient panel. I know, I was shown the panel and it was an antique. Screw-in fuses. The voltage to the garage was dismal. I could tell by the welds. It didn't go well.
If you're on an extension cord, even if the voltage at the receptacle is robust, that cord needs to be fat. Anything over 25' ought to be 10 ga. 100' feet is out of the question for 120v unless you need a wheelbarrow to carry the cord.