Hello!
Jesse from the Guru Team here.
It looks like Sellbrite doesnt yet support international marketplaces according to what I could find in their support documentation: https://sellbrite.zendesk.com/hc/communities/public/questions/201200610-Currency?locale=en-us (this info may be out of date, but its a response to a query about currency formatting from someone looking to use Ebay UK)
But an app like https://apps.shopify.com/inkfrog-open definitely supports Ebay UK.
Something like ChannelUnity https://apps.shopify.com/channelunity may be worth looking into as well.
Feel free to reach out at any time if you have any other questions.
