Official rule text
78.3 STEP 1—ANTI-FIGHTER BARRAGE: If this is the first round of a space combat, the players may simultaneously use the “Anti-Fighter Barrage” ability of any of their units in the active system. a If one or both players no longer have ships in the active system after resolving this step, the space combat ends immediately. b Players cannot resolve “Anti-Fighter Barrage” abilities during any rounds of space combat other than the first round. c This step still occurs if no fighters are present.
View official source
Source: Living Rules Reference and FAQ - Prophecy of Kings
Expansion: Prophecy of Kings
Version: 2.0
Reference: Rule 78.3