Commission

On whose name the invoice will be raised to the customer.?
Is it on your name or on that person name.?

I am asking not to whom.?
I am asking by whom.?
In the invoice on whose letter head(supplier name) will be shown.?

So, it comes under principal and agent and as the invoice is being raised on the name of principal, you can just show it as two supplies - One is between principal and customer via agent and other is principal and agent for commission
So, show two supplies in GST and pay the amount in GST