Need some help !!!

I have H1B Visa and i am planning to Visit Nepal later this month, and I heard i need Labor Certificate while returning to US, if not there will be problem in Nepal airport.

Anyone out there who can help me what kind of documents do Nepal Government will ask in order to issue Labor Certificate.

Thanks

नेपालबाट H1B मा US आउने बेलामा Labor Certificate बनाउन के के documents चाहिन्छ?