As per the documentation How to use SendGrid in Azure Functions, we need to create an entry for the SendGrid API key. The documentation contains a screenshot of a panel called "Application settings" that appears to not exist anywhere (perhaps the documentation isn't being kept up to date with the UI...).
I have however been able to create keys in 3 other places that seem appropriate (again, the UI seems pretty poor and I'm having to guess here).
Please can someone advise on this?
