How queue trigger based Azure function failover to secondary when RA-GRS enabled storage account's primary is location down?

Question

Enabled Azure storage account with RA-GRS replication which enables read from secondary when primary goes down.

There is a queue triggered Azure function listen to the queue which is configured to primary region. Now if primary region not available, how the queue triggered Azure function can failover to secondary region?

Also once when primary is up & available, how queue triggered Azure function can failback to primary?

P.S: we are using Azure function out-of-box input bindings & triggers in out implementation.

          public class MyFunction
                {
                    [FunctionName("samplefuntion")]
                    public async Task Run([QueueTrigger("%QueueName%", Connection = "QueueConnectionString")]string queueItem)
                    {
                        LogDebug($"Started processing queue item: {queueItem}");

                        ....................

                        LogDebug($"Completed processing queue item: {queueItem}");
                    }
                }