Send Email Reminder notifications to all the Approvers after 24 hours via custom servlet prcoess

I have created a custom servlet to send workflow notification to all the Approvers using this thread How to use custom email template in a workflow step?

But now another requirement is to send email notification reminder again to all the approver after 48 hours to approve the workflow. I am looking forward for a solution as how this can be done using custom servlet in AEM 6.2 workflow

@Reference

    private ResourceResolverFactory resourceResolverFactory;

    @Reference

    private WorkflowService workflowService;

    @Reference

    private MessageGatewayService messageGatewayService;

    @Override

    protected void doGet(SlingHttpServletRequest request, SlingHttpServletResponse response) throws IOException {

}