I am following the tutorial here: Create a Travel App with SAP Fiori Elements Based on OData V4 RAP Service | SAP Tutorials
But instead of using Business Application Studio, I am using VS Code with Fiori Tools.
Connecting to the TRL trial system is successful; I am also able to use the Fiori application generator to connect to the system, retrieve my service’s metadata, etc.
When launching the preview, it first opens a browser window to connect to the TRL system which is successful.
Then it opens the preview browser tab with the sandbox and tries to open the app, but this fails.
In the browser console log, it shows that it failed to retrieve the metadata from the backend via the proxy that was started locally on launching the preview.
The debug console and terminal in VS Code show nothing out of the ordinary.
The only change I usually have to make is to set ignoreCertError: true in ui5.yaml, because I am behind a corporate proxy, though this normally works for backend connections.