SPECIAL abilities - Big fan (Fallout 76)

Healthy people! Initially, I tried to look for answers on the network myself. I went to the Bethesda forum, but it turns out they closed the forum (hand face) The Goha forum for Fallout 76 is also dead. In general, either tell the forum about the game or help with the answer. Tell me how to unlock the "Big" cannon fan ability in the Strength tree. I pumped "Powerful Strike" and "Powerful Strike Expert" to the maximum, got level 30, but this perk is not available when choosing an ability in SPECIAL. As I understand it, it may be necessary to open some other abilities before that. But nowhere did I find information what exactly ?!