GLTF with decal not aligned with mesh

Hi, im kinda new to 3d models and threejs and i want to know why this is happening

I want the react logo to appear on the back of the shirt. The decal is not aligned with the shirt mesh and i dont know why, i tried to fix it in blender but i couldnt find a solution.There is like 5 px gap between the decal and the shirt, even if i change the decal z coordinates it doesnt change.