Youtube API woes

Hello Again,

Apologies if I am missing something obvious but I am still having a problem seeing youtube data on a page using the API. Just to clarify, I have successfully followed the unsplash tutorial which was great, so have tried the same but with Youtube data. The API settings appear to be correct thanks to earlier help from Paul and George on a previous ticket so am at a bit of a loss again.

To test the connection, I tried binding the image source to the thumbnail URL (items[0].snippet.thumbnails.url) just to see if they would load but nothing happens.

Best regards,