"We buy this equipment from Japan." = not accepted. Reported.
There is no indication of past so not sure why "buy" couldn't be accepted.
No indication of tense, so yes "buy" should be accepted
English translation not good. You buy something 'in' a country. I know membeli means buy but do they mean the equipment was 'brought' from japan?
Had the exact same thought. Although what could be meant is 'We buy/bought this 'equipment from japan' - as in 'made in japan'. Although in that case I would literally mention the made in Japan. Else I'd go for We buy/bought this equipment in Japan.