Do I need a commission card for my custom-built sales channel on Shopify?

[gvlabate]

we're building our own shopify sales channel to let shopify merchants connect their store to our standalone marketplace application.

in building a sales channel (https://shopify.dev/docs/apps/channels), i read that "The app prompts the merchant to agree to any commissions or fees. Use the Billing API to make charging for your sales channel app.

my framework is the following. orders and payments are handled directly on my marketplace application, and the merchant is only charged there via a commission on each sale. therefore, at the moment, we're not using the Billing API to charge the merchant.

my question: in this case, do I need a commission card on my Shopify sales channel at all?