This is the advice my mum, who has stage 3/4 kidney failure follows. https://www.kidneycareuk.org/documents/178/Healthy_diet.pdf
I’d be wary of any fish preserved in salt, or even with a really salty taste, like anchovies or smoked mackerel, because salt intake should be low.
(When I say my mum ‘follows’ this advice, I mean that very loosely……)