Opacity Missing channel

[NitroGamerXD26981840las2]

This is the First time I am exporting textures but after i export it ive been having this right here 

For some reason i cant find the problem i added opacity channel on the the texture set settings and nothing is working is i check to see if there is something wrong with the input but i dont know what im looking for here is the configuration i tried to use the opacity one but it still doesnt work

Tf2 paint i use 

[NitroGamerXD26981840las2]

Never mind i Fixed it you have to use FBX file instead of OBJ

[edd29435859bs7y]

I'm using fbx file and still have the same error