I believe you use an atribute , but apply proficiency if you have the tools...
Yes, but that confused a lot of people because nearly all (though not all) tasks have a skill defined with them, and sometimes you have both a skill, AND a tool, that would be appropriate. (The most obvious example being Performance, and Musical Instruments). Xanathar's Guide suggested that when THAT happens, you can roll the Skill with Advantage.
I'd say Navigator's Tools would do that with Survival, if you have both.
It's terribly inconsistent, which is my main problem with the skill system. The system works "good enough" but I don't think it would be very hard to come up with a better one.
Of course, this is all moot if no one in the party has Navigator's Tools, and proficiency in them. Qawasha's gear is not mentioned anywhere (like most NPC monster stat-blocks, he's expected to have 'whatever makes sense') I think it's pretty possible that he does have whatever a Chultan would use to navigate a jungle, and it's pretty well established that the Sticks have a map*, though we'll be moving off of it very soon.
* At least, I can't imagine that you wouldn't have gotten a copy of Tarri's map when you escorted her to make it.
At any rate, I would not object if it were argued that Qawasha can roll his navigator's survival checks with advantage (from whatever tools he uses).