Deductions & credits

to whom who can help me,

 

I’m a green card holder that works in international organization ( IMF). Im exempt of taxation as my salary is net of taxes. I would like to know how to report my income as wages and if I can do it online and attach my employment verification that states the treaty and that Im exempt of taxation. I used to pay someone to do it and he made me mail my tax return. Could you please tell me what where I should