Unless you work on a dysfunctional team and any non-tracked work is forbidden, and any work you try and get tracked requires 6 pages of justification and takes 10 weeks to get prioritized enough for someone to work on...
My team isnt dysfunctional but I always get hit on the head for doing work and not making a ticket. I don't get it, if I see something bad I'm not going to search which ticket would best fit this issue. Just reviw my PR ! Also, so far most of our projects start simple but end in chaos and deadlines on the minute. I feel like we could always do better.
I mean, finding a Jira epic/project where to fit my ticket is not the hardest part of the job tbh. Also, depending on the team and your experience, loosely fixing things here and there can be a red flag or totally the opposite (e.g., I've seen how juniors or people in general with less than a decade of experience get punished when they start fixing random things here and there. On the other side seniors or staff engineers get kudos for fixing also random things but in less volume and usually more tricky ones).
Having a ticket to back up your work is never going to hurt you, though.