I think I’ve seen it in the local ethnic store, and the flour too. But it’s just called ‘cassava flour’. Is that the same as ‘tapioca flour’?
It’s the same thing as far as I know. And the concerns I mentioned apply if you buy the whole root, not the root processed into flour (it’s already been processed).
Ethnic stores are a godsend btw. You can get stuff that would normally be labelled as “gourmet” in a regular grocery for dirt cheap.
This informative article includes the differences between tapioca flour and cassava flour:
https://www.bobsredmill.com/blog/healthy-living/what-is-tapioca-flour-where-does-it-come-from/