Developers are experiencing issues where checkout UI extensions work correctly in local development but fail to display after deployment to production stores.
Common deployment steps attempted:
Generate extension via Shopify CLI
Test locally (works fine)
Deploy using npm run deploy
Create app version in Partner Dashboard
Deploy web app to hosting (Heroku/Nginx)
Key problems identified:
Extensions not appearing on checkout pages post-deployment
Cloudflare URLs being used instead of configured app URLs
Extensions requiring manual preview enablement to update URLs
Potential solutions mentioned:
Enable “Development Store Preview” in Partner Dashboard under Extensions
Manually add the app block to custom checkout after deployment (easily overlooked step)
One user notes the tooling seems designed for solo developers rather than team workflows
Current status: Multiple users report the same issue across different timeframes. Some are awaiting support responses (one waiting over a week). The discussion remains open with no definitive resolution, though the preview enablement workaround shows promise for some cases.
Summarized with AI on November 1.
AI used: claude-sonnet-4-5-20250929.
i have deployed my app on heroku and then i deployed extension with cli command “npm run deploy” and create a version on partner dashbord , then i expected my extension will integrate with checkout page
Ps: the extension runs well locally
Actual behavior
after doing all those steps my extension wont appeared on checkout page
Reproduction steps1. run “npm run shopify app generate extension”
update extension folders
run "npm run dev "to make sure that works fine
run “npm run deploy”
create a version of app extension on partnre dashbord
We have the same issue - extension working fine locally testing via ngrok - but we cannot get our checkout extension to display… I have contacted support and am hoping for some help from them but have been waiting a week now…
I’ve had a similar experience, I’m tasked with creating a checkui extension for a client but I work as part of a team, we have multiple people that would like to review and sign off on extensions before they get published to their store? It looks like checkout ui development tooling is geared toward the lone development? I’ve published a copy of the app to a server running with Nginx, I then locally authenticated on behalve of the deployed app, I was able to publish the extension and enabled it for preview. When I go through the checkout process on our UAT store it looks like the store is trying to load the extension from cloudflare rather then the configured app URL running on a fixed domain on NGINX?
Pretty obvious but this one had me scratching my head for about 20 mins. Did you add the app block to your custom checkout after deploying? I completely forgot and was foiled.
Hello, I am also facing the same issue I created a UI extension using Shopify CLI, and it is working fine locally but the problem is the same as you, it is trying to access the previous Cloudflare URL until I select the extension from this options preview link(refer image), only then the cloud flare URL is updating. Due to this, it is not working when deploying. Do you know how to solve this?
I’m facing the same issue. I have a checkout extension and a theme extension. Checkout extension not loading. How do i add the app block to custom checkout. can i know the steps
