If you own Palico Paintballs (Blue Paintballs), then fulfilling the following conditions will let your Palico automatically use Palico Paintballs to mark monsters:
"Adventure Sync" is enabled.
Walk a certain distance.
Please see details of Adventure Sync settings in this article.
Notes:
The ★(star) of the monster that gets marked is randomly determined from the star levels you currently have unlocked.
Any unused Palico Paintballs will not carry over to the following day.
If GPS usage is restricted on your device or communication line, such as power-saving mode or bandwidth limitation, your Palico may not be able to mark even if "Adventure sync" is turned on.
(Updated on September 24, 2024) Even when Adventure Sync is disabled, your Palico may automatically mark monsters while the app is displayed on the screen.