Stripe Connect

So I currently have Stripe set up and all transactions are being made properly in test mode.  So now I need to further configure how transactions are being made.  My users set up their own individual marketplaces on their profile and what I need to do is have processing of all transactions to go through a central point which seems to be done through the stripe connect button in the cart.  So what I need help configuring is how to make the only option for payment processing creating/connecting a stripe account to my platform stripe account so I can take commission etc.  As of right now upon payment all dollars are processed through my Platform Stripe account and I have no way to know whom the product was sold by etc.  Currently when a user tries to sell a product they are prompted to pick a payment processor and there are several to choose from.  I have been pointed to the article on how to set up a commission based marketplace, and although that has helped me with the "what" of it all, I am pretty stuck in the weeds on how to actually configure it all.

Thanks in advance for any help!