Dragonsteel from Ice and fire requires a Tier 8 hammer
but I don't know how to get that

I have a forge hammer with two combustion chambers and it doesn't work it says tier 7

datapack where?

playing on 1.19.2 and it requires level 10 - impossible even with toolboosters

It's now level 9 required!

This is intentional behavior. Some materials are sufficiently high level that not all parts can be made out of them.

If you'd like to change this, you can overwrite the dragonsteel materials using the datapack attached to 1.2 on CurseForge; reduce the 'requiredTools' numbers and the required hammer level will decrease.