ok i get the issue, vr
i didnt know what you were planing to do with it.

ok instead of using surface shader, assign a regular Lambert shader and try to import in vr. Also maybe dont use .png, use a normal jpg image. Try it out

if it is still dark in vr, than in material attributes of the lambert material change the value of ambiant to maximum and try to import to vr. this should work

if it still doesnt work than check vr system you are using. it really depends from the vr system.