I losing my mind with this speed boost crap

Im losing games to kids EXCLUSIVELY using that dumb ass boost shit to score goals. I’m to the point where if I can’t beat em, join em.. and I can’t figure out how the fuck to do it. Hold LB, let go and sprint.. I know what to do but my players just don’t fucking do it. I have Nico Williams, who I just got obliterated by. Dude had 5 shots and 5 goals, all from that dumb ass speed boost and I can’t for the life of me figure out how to do it but other people seem to be able to do it with ease. HOW DO I DO IT?

I’ve made it this far without doing it but I can’t take it any more, that’s literally the only way people score so if I don’t do it, I will lose games. How do I do it? What am I doing wrong?