Need to add Our Third-Party Credit / Debit Card Providers

we are new Third-Party Credit / Debit Card Providers and need to integrate it with Wix
let us know the procedure

See Example: Stripe Payment Processing as an example of integrating a payment processor into a Wix site.

For Wix Store, you cannot add it INSIDE the Wix native checkout page, but you can add it to the thank you page

See this example site for idea: wix-payments.com