I don't know about income tax reports, but Paraguay does not tax income received from outside of Paraguay.
When I applied for my permanent residency, I also asked at the Legal department of Immigration whether I could legally work online (receiving income from outside of Paraguay) before having my permanent residency (carnet) and cédula (ID card/work permit).
The answer was yes, no problem, as long as the income received was not from a Paraguayan source.