Hi @DSR2,
Shopify has several methods to adjust the API version used for web hooks for your app. You can amend it in the API with a PUT call https://shopify.dev/api/admin-rest/2022-04/resources/webhook in REST , or you can update the Event Subscriptions version in your Partner Dashboard.
See here https://shopify.dev/apps/webhooks/versioning
In this case it looks like you are attempting to update the Webhook Subscription version from the Apps section in the store admin which is also possible but you need to have the correct permissions enabled.
https://help.shopify.com/en/manual/apps/custom-apps
In this case it looks like you might not have the 'Develop App's scope enabled for the store and that's why you are seeing the read only message.
Please check you have the Custom Apps permission enabled on the store.
https://screenshot.click/16-07-qgq96-s28z7.png
You can read how to enable this scope in the admin here
https://help.shopify.com/en/manual/apps/custom-apps#:~:text=for%20custom%20apps-,Enable%20custom%20a...
We hope this helps!
