I don’t think there is any good way to test UBI at any small scale, I think there needs to be a critical mass of people who can pay their housing and food costs how society and economic activity would be reshaped under such a system.
Find one or more persons who _you_ want to support and support them with a basic income. If UBI works, they will also start supporting other people. Sooner or later, you have an economy of people who support each other with UBI.
Chances are that you are unlucky and your choice of seeding persons wasn't good. But for science, that doesn't matter. If others copy that approach, sooner or later, a working economy will emerge - if UBI works.
There is no need to establish UBI in an area even though it helps. Thanks to the internet, the economic connections can all be organized online.
*edit: marked the _you_