Question Replacing an area on a texture with a transparent texture

To make it clear what I'm trying to do. I am trying to implement the placement of a tattoo on a body area. Which way I went: there is a base texture, there is a texture with green circles which helps to find the desired area. Then I replace the green area with my tattu. The problem is that my tattoo has a transparent background, but in the shader I get a white background.



how to make the background transparent?

 

You need to set the shader to transparent, then an alpha node will appear in the fragment block. If it doesn't, right click the fragment block and add node->alpha

then, pass 0 to alpha where the tattoo is or something