US tax requirement for non-resident non-citizen receiving donations from US non-profit

My wife and I do volunteer charity work in a third-world country. We are not US citizens or residents, however we have recently partnered with a US-based non-profit 501(c)(3) organisation who are set up to receive and receipt donations and disburse to us.

This disbursement is sent through to us the end of each month, and at the end of the year we are issued a 1099 form (well this is what I’m told – the arrangement is new so this hasn’t happened yet).

My question is what do we need to do to satisfy the US IRS (if anything) when we receive this 1099 form? Do we need to file taxes? The non-profit says that when they disburse to US citizens those people have to file that on their taxes, but since we’re not US citizens we’re not sure of the actual requirement.

We do not have a SSN. We do have a bank account with a US bank which is where the disbursement would be sent each month.

If it’s relevant we have B1B2 visas for the USA.