Error type: "Bad Request". Error message: "API key expired. Please renew the API key." Domain: "global". Reason: "badRequest".

Did you added your own Google API key? Look at the help.

Check in YouTube if the id PLbPTI55vtiGvtERVqNoDTbYAvzP3alk7G belongs to a playlist. Check the FAQ of the plugin or send error messages to support.