Skill not usable with skill gem equipped

I have Blazing Salvo skill gem equipped, however the skill itself does not show up on my skill tabs. I am unable to use it. I am playing on playstation.

Are you aware that you can reassign skills to different buttons?

Once the four default buttons are used, there's an additional set on R2 + button and L2 + button.

You can reassign which skills are on which button either directly (using R3, IIRC), or from the "Skills" section of the menu.

Just an FYI, I don't recommend having any skill assigned to X, as sometimes it can cause issues.

I did not know that. However the skill does not appear there. Ive remove all skill gems except blazing salvo and still doesnt show.