This may sound silly but it’s helped me… my old Jack has now sadly passed but he was terrified of fireworks and thunder. Thunder jackets and validation helped but he would shake throughout the noise. I didn’t want my two chihuahuas to be scared and I wanted to try a new angle for dealing with fireworks.
I encouraged them to be annoyed by the noise:
“
You tell them fireworks babies woof woof good boys woof woof! That’s right, let’s have a treat now and settle down.”
I encourage a little woofing from them, to fight back at the noise and then settle them down with praise at having fought the naughty noises. So now they get bolshy with fireworks and not scared. Perhaps not the best approach but it’s worked for my boys