Appeal at 1st Base

[Stair-Climber]

Keeping in mind that a missed bag is assumed touched until the appeal. How does the live ball appeal work for missing the bag at 1B? My guess is this: B/R beats throw, but runs past 1B and misses orange bag. Throw arrives to F3, who is touching 1B. Is that the appeal--F3 catches the throw to 1B before B/R gets back to touch the missed bag? Or does F3 need to communicate something to umpire about an appeal while touching 1B while in possession of the ball?