Mind that a Basic Income Guarantee is not the same as a basic income.
Discussion of either is primarily about tax reform, and not a structure to provide payments directly to each adult human on the planet, which is required for a truly universal basic income.
I believe the simplest, and most direct method, would be to require sovereign debt to be backed with Commons shares, that anyone can claim for deposit in trust with their bank.
This way each person would recieve an equal share of the interest on sovereign debt, and the only government involvement would be making their debt payments.
If wealthy countries provide payments only to their citizens, then the poor countries get even worse off, and the wealthy countries may continue to exploit them.
Providing enfranchisement to all, in the form of a secure share, establishes the sovereignty of each person.
It really is all about the rainforest