You do not pull anything with one finger. Press the trigger straight to the rear. Do not pull it.
Fit first
Your hand has to fit the gun. Your trigger finger needs room to reach and work the trigger. If the gun is too big for your hand, accurate shots get very hard.
Press, do not pull
Thinking pull creates sympathetic movement in the wrist and hand, and the gun moves with it, sending shots to the side. Move only the last joint, the fingertip, not the big knuckle. Keep a little space between your finger and the frame so you are not dragging the frame as you press.
Pin to the rear, then reset
Press through the wall and hold it back. Then slack out only to the reset, the audible click, and press again. Minimal finger movement. This is what beginners should learn first; it stops them slapping the finger off the trigger.
Slacking out under recoil
For speed on a generous target: press, ride the trigger back to the wall under recoil, and press again. Learn both this and the pin-and-reset. You never have to rush; you can hold at the wall or the reset as long as you want, and the gun will not fire until you press through.
Why it matters
Jarrod can take his support fingers off the gun and still shoot accurately, just the trigger finger and the sights. That is shooting. Everything else is for follow-ups. Sights and trigger, and the trigger is the most important.
There is no secret sauce. The sauce is training. Dry-fire the press thousands of reps, 4,000 to 5,000, to build the trigger-finger discipline that keeps you from crashing the trigger under stress.