Is there a way to send reminder notification after 24 hours if it is not yet responded, and send another reminder notification every 4 hours until it has been responded? This should only be done inside a Flexi Task since the users can respond using Lazy Approval. Unless there are other action that can send an email with Lazy Approval.
if I understand you correctly you want to start sending reminders after 24 hours and from them send a reminder every 4 hours. Is that correct?
I don't think that will be easy, for two reasons. Obviously you can configure Reminders within the Flexi Task, but you can only configure a fixed interval. So every 4 hours would be possible or every 24 hours would be possible.
On the other hand you could use the Task Reminder action, as is described as Method 1 in this document: How to configure reminders and escalate a workflow using delegation . You would need to combine it with the Reminders option in your Flexi-Task to get the achieved result. For this approach to work, you would be needing the Action ID from your Flexi Task. But, at least as far as I know, the Flexi Task populates the Task-ID Field only after completing the task, so, sadly, this won't work either.
I know there is customer feedback on the action-id issue (Populate task id as soon as the task is created – Customer Feedback for Nintex ) but I don't know the status of that issue.