If you scroll down on this page
http://nepal.usembassy.gov/visas/non-immigrant-visas/applying-for-an-niv-in-nepal.html

How to schedule your visa interview    

Nabil Bank is responsible for collecting the visa application fee and scheduling visa interviews for the U.S. Embassy. Please do not call the Embassy's consular section for any appointment information. Applicants should bring with them to Nabil Bank the following items:     

• A valid passport
• A clear printout of the completed online visa application’s
     confirmation page (with bar code),
• The equivalent of $140 (for B1/B2, C, D, F, I, J, and M visas) or $150 (for H, L, O, P, Q and R visas) in Nepalese rupees to pay the visa application fee.

Please note: the application fee is a non-refundable administrative processing fee. It is collected whether or not a visa is issued.