If you no longer need a Marketplace integration or want to reconfigure it from scratch, you can remove it from the Installed list. The integration will stop working immediately, but you can reinstall it from the Applications page at any time.
Go to Settings → Market Place → Installed.
Click the eye icon in the row of the service you want to remove.

On the service detail page, click Delete.

The service is removed immediately, and its connection to the platform is disabled. Any automated processes that relied on it – such as currency rate updates or email notifications – will stop until the service is reinstalled and reconfigured.