How does one submit an Azure support request?

I purchased a support plan. But I can't find the page where I can submit a support ticket.

I have submitted tickets in the past. But can't figure out how it works now.

My Logic App stopped working 4 days ago. Nothing was changed by the developers.

Last 10 entries (those in last 4 days) show as failed in Run History and have this message in the "Execute CSharp Script Code" action

InvokeFunctionFailed

The function 'CSharp_receive-email-test_execute_csharp_script_code.csx' failed with the error 'Exception binding parameter 'context'' when executing. Please verify function code is valid.

Again, no code was changed. And I can't make sense of that error.

Was there a breaking change made to Logic Apps inline C#?

I changed the inline script to just be the sample on the page https://learn.microsoft.com/en-us/azure/logic-apps/add-run-csharp-scripts

But even that results in the above error.