I am following the example mentioned in the readme, but I get this when trying to install or access the app

I can see that the online auth path is hit, and it redirects with
ctx.redirect(/install/auth/?shop=${shop});
From web server logs, I can observe that this is then hit :
"GET /auth/callback?code=aeccdc[...]"
Any clue to what that above error indicates? Do I need to set some specific allowed redirect urls in the Shopify app setup web ui?
thanks for any hints
I am following the example mentioned in the readme, but I get this when trying to install or access the app
I can see that the online auth path is hit, and it redirects with
ctx.redirect(
/install/auth/?shop=${shop});From web server logs, I can observe that this is then hit :
"GET /auth/callback?code=aeccdc[...]"
Any clue to what that above error indicates? Do I need to set some specific allowed redirect urls in the Shopify app setup web ui?
thanks for any hints