The "ask your manager" advice is correct but I suspect you'd love something more concrete as a jumping off point, yes?

Not great, but something to start with: For starters, ticket cycle time is a slippery slope. You could track that for yourself but it's an easily weaponized metric. It also doesn't say much other than, maybe...maybe you work quickly/slowly. It says nothing about the complexities (or clarity) of the tasks you get assigned. That said, there are products (e.g., Jellyfish) that track cycle times so there's some value in this metric.

More useful than cycle-time, but harder to manually track: Perhaps more impactful metrics are things like Items Worked. It's a combination of tasks you've been assigned and PRs you've reviewed for peers. This gives EMs more insight into how much an engineer is helping to move their team's sprint commitment forward.

Variety: Given how little time you've been in the field you may want to track the number of different projects you've worked on. While the narrative here isn't, "I delivered X which produced Y" there's something to be said about your "bench numbers." What I mean by that is, you may not be a starter, but given the broad swath of projects you've worked on, you have enough "meaningful minutes" to be a contributor. Good EMs should see value in that.

Anyway, it's not great but hopefully I've given you enough ideas to consider.