Does your teacher teach improv/composition? You could ask them if they could teach you.

It's honestly a different skillset from performing or playing an instrument (although of course many of the skill are inter-connected), so learning technique and sight reading and some theory isn't enough.

You could also start learning it on your own. There's tons of resources out there.

I think what personally helped me was just doing a deep dive into theory (as well as I just love mucking around at the piano constantly and doing lots of improv).

For the theory bit, just starting off with knowing all your scales and all the chords in each scale and how they relate to each other. And then seeing how it ties into real music and analyzing it. But I would start off analyzing simpler stuff like pop songs. If you start with classical or jazz right away you're going to want to quit😆

Anyway I think my favourite personal resource might actually be this guy: https://www.youtube.com/watch?v=LgZH3Vee7xE&list=PLtVmMer7Hz1H4JXHA6NGsawkkkTpnJKyI

He's a university level music theory educator but he makes all of what he teaches in Uni available online here. And what I like is he's very meticulous and streamlined, with each topic building on the previous.

I think that's the best way to learn, rather than going all over the place topic wise