So, I'm not a JQL master... I think I use max once every two - three weeks... LOL.
That means I get stumped easily on really easy basics and so here's a dump question:
How do I search DONE issues that do NOT have a fix version...?

This JQL is good and gets desired result:
project = "ENVIS" AND statusCategory = Done ORDER BY updated DESC
This JGL is NOT good and I get a warning message:
project = "ENVIS" AND statusCategory = Done AND fixVersion = "None" ORDER BY updated DESC
The value 'None' does not exist for the field 'fixVersion'.

My gut feeling tells me I should be pouring through this in more detail:
https://confluence.atlassian.com/jiracorecloud/advanced-searching-765593707.html
But I'm lazy, love hanging out on Community, and I'm sure someone would LOVE to get an extra Accepted Answer today....! 😉🏆