Any API or package for merging textures at runtime?

Hi everyone,
I’m using Daz3D/uDTU HDRP.SSS for my character’s head material in Unity. The issue is that it only supports one makeup texture for the Base Color Map.

I want to allow users to choose between multiple makeup styles and combine them dynamically onto the base texture.

Are there any Unity APIs or asset store packages that can merge textures at runtime? Or do I have to write a shader/Texture2D blending script?

Any guidance is appreciated! Thanks.