I have looked through documentation for WebJobs, Functions and Logic Apps in Azure but I cannot find a way to schedule a one-time execution of a process through code. My use
One option is to create Azure Service Bus Messages in your App using the ScheduledEnqueueTimeUtc property. This will create the message in the queue, but will only be consumable at that time.
Then a Logic App could be listening to that Service Bus Queue and doing the further processing, e.g. SendGrid, Twilio, etc...
HTH