Custom service usages for charts and reports

Good day!
Currently, I am working with ManageIQ and I am very interested in integration with custom usage collectors. What is a process to add a brand new meter which can be shown in charts and used in reports? Perfectly I am looking for something which has minimal code changes in the main manageiq repo.
example: I want to add serverless meters to charts which can be charged afterward. I want to write my own collector which will save datapoints into manageIQ database and they will be manageIQ friendly.
I would be super thankful for an answer and maybe some guides which were missed by me.

best, Oleksii