Anyone knows where to look into to fire a combat message?

[Ukoku]

I am making a mod with where units take damage each turn near a specific unit. I got the mechanic somewhat working, but I can't seem to figure out how to fire a combat log for the damage dealt this way.
I did find the notification manager, but it seems to only show notifications on the right side? (Correct me if i am wrong )
I am wondering If anyone knows a dlc scenario/mod that might added customized combat log that i can look into? (Of course it would be even better if you know how it works !)
I appreciated any help! Thank you guys in advance!