Can a dismissive avoidant change?

I am personally a fearful-avoidant (I think, I thought I was dismissive until reading further into it), but my partner is dismissive-avoidant. I am working on it, as I acknowledge it's an issue to work on. But while my husband has at least agreed to work on our relationship, I don't know if I can get him to agree to work on himself. He's very much a "it was what it was" type of person. Like, accept it and move on. Better to forget/ignore than evolve. But at this point I know I need him to agree to self-inspection/evolution for our relationship to evolve. So can a dismissive-avoidant change? (I feel like the answer is going to be "only if he wants to" or "only if he can acknowledge the problem", so now it feels more like a rant, sorry.) Any self/partner stories are welcome.

Tl;dr: don't know if my dismissive-avoidant husband can change and hoping he can.