Restricted Network access in Checkout-ui extension

We are currently building a custom credit card payment extension to provide additional options like installments, etc during the checkout.

By enabling network access in test stores, we were able to make Rest API Fetch calls to outside shopify server. Rest API calls are required to pass the card bin number to fetch the appropriate installment plan based on the buyer card bin.

The issue is when the extension is submitted for approval, network access was restricted for live stores.

Plan:
The extension what we build will add value to the buyer checkout experience based on the card bin entered by customer during live checkout.

We have also explored metafields option which doesn’t suit for the above requirement.

Looking for help from the community!

Have you been invited to become a payments partner?

Yes, we are a payment partner

Since the partner support link in the Support page is broken, can someone help me find the right way to contact the team to resolve my above query on Network access restriction?

partner support hyperlink redirects to https://help.shopify.com/shop-select?orgId=xxxxxx&returnTo=/partners which is down