Group session pay

Hi everyone! I currently work at an agency (accepts most insurances and medicaid, most of my clients are medicaid) and am trying to speak to management for a pay raise as I completed my hours towards licensure. The practice wants me to run a group and is trying to make the group a part of the raise which isn’t a norm for others. I wanted to ask everyone who run groups about how do you get compensated for them and how much documentation time do you require each week?

Is it better to ask to be paid separately from a base pay for running a group or is it better for it be a part of my base pay?

Thank you so much!