As a tech lead, with little to no Agile processes, how should I track work and assignment in Jira when there's a clear delineation between front-end and back-end developers?

I recently started as a tech lead on a team where I have one front-end and one back-end dev under me and I'm still trying to figure out how to navigate it. It's my first leadership role.

Previously, I worked on teams with full-stack devs and proper Agile structure in Jira with regards to user stories and sprint teams. We'd assign a story to a team, and one of us devs take it.

At the new job, sprints and stories aren't a realistic goal, and I'm trying to improve their Jira usage and team process which currently are pretty much... chaos.

If you had one FE one BE devs, how would you track work? A Jira ticket can only be assigned to one dev, but almost every new feature requires work from multiple devs, and we don't have sprint teams. I'm about to start creating individual little tickets to track FE and BE work but that seems like too much... Another option is to assign tickets to myself and then try to work with my devs on Slack to follow what they're doing, and that feels too informal...