Source: Starfinder Core Rulebook p.121
As a standard action, you can spend 1 Resolve Point to temporarily learn how to use a weapon in combat. Choose a single weapon; you gain proficiency with it (and any identical weapon) for a number of minutes equal to your class level. Each round you use the weapon reduces this magic hack's duration by 1 minute. For example, at 4th level, you could gain proficiency with corona laser rifles for 4 minutes. If you fire such a weapon for 2 rounds, you remain proficient with it for 2 more minutes.