How to create custom multiple textures for tools

I am trying to create custom tools and I am looking to add custom textures to them, using the minecaft style. but when I try to add more than one texture to the tool it just shows the previous texture again,
Is it even possible to have multiple custom textures for a tool?
Btw I am running 1.20.4 PaperMC Server with the client running 1.20.1 with the help of ViaBackwards and ViaVersions