IMHO, you need a transparency mask.

I'm told you can configure Material, Advanced, to use a PNG's Alpha channel as-is. I'm still learning that route.

Your guy's PNG does not have an Alpha channel 'mask' for his face, it's entirely white. So, gotta craft a stand-alone mask...

I pulled the pic into free, remarkably nimble Irfan View. Flood-filled the white surround to black with edit's 'paint' tools. Used 'image' tools to replace the face colours with white until only eyes and mouth remained. Back to 'paint' tools, brushed away the left-overs. Saved file under different name, to be sure, to be sure...