I have confusion around which issue type to be used for certain activities.
There is an activity called "Payroll processing" where I need to verify the GL files received from UKG system and start executing the Integration process to convert them into the format accepted by legacy payroll systems.
This is not an issue, or change request, it should be treated like a task. But timesheets will not accept the time logged under Internal task.
Could you please suggest how this kind of activity can be logged in timesheet?
Welcome to the Atlassian Community!
This is not something the Community can help you with. We don't know what your organisation's processes are or should be.
I think you need to ask the people who are asking you to go through this process, we can only help you with the general principles of Atlassian usage, not how your organisation is actually using it.