How to add external payment gateway after Shopify's new checkout extensibility.

Topic summary

A user is trying to integrate Cryptomus, an external payment gateway, into their Shopify store but cannot find the “Additional script” field that older tutorials reference.

The Issue:

  • Traditional methods for adding custom payment gateways (via script fields) are no longer available due to Shopify’s checkout extensibility updates
  • Cryptomus does not appear in Shopify’s built-in payment gateway options

Suggested Solution:

  • If a payment gateway isn’t available in Shopify’s search/selection menu, it must go through an official review process
  • The payment provider needs to apply to Shopify to be reviewed and potentially added to the platform
  • A reference thread with more details on implementing external payment providers was shared

Status: The discussion remains open with no immediate workaround for adding unapproved payment gateways under the new checkout system.

Summarized with AI on October 29. AI used: claude-sonnet-4-5-20250929.

Hi, literally all the tutorials show to use Additional script field to paste a code. but In my case I did not find any option. then how do I add external payment gateway. I want to add cryptomus payment in my shopify but seems I do not find any option for that.

Hi @ruspie I believe if a payment gateway is not in the search option, then you would need to apply to have it reviewed and possibly added check out the marked reply in the thread here https://community.shopify.com/c/shopify-discussions/implementing-an-external-payment-provider/td-p/898323