How to create an approval work flow in the form.

When the approval email gets sent to the "approver" I need the approval email to be sent, if approved or the denied email sent if the request has been denied. 

I have checked your form and it seems the notification email has the edit link.

However, you have set your Order Approval field to hide.

Kindly add a condition to show your Order Approval when the form is edit. You may use your Get Page URL to show the field.

Sample condition Screenshot:

Now the Order Approval field is shown when the form is edited.

You may also check this guide:A-General-Approach-on-Building-an-Approval-Process-Workflow

Please give it a try and let us know if you have further questions.

Sorry, this is still not working 

I would like the approval email to be sent to the user, if the "approver" selects approve 

I would like the denied email to be sent to the user if the "approver" selects decline

Sorry, it seems like the link to the guide is blocking. Please check the link again: https://www.jotform.com/help/432-A-General-Approach-on-Building-an-Approval-Process-Workflow

There you will see the example of how to create the condition to send the "Approved" notification:

And how to send the "Denied" notification:

Let us know if you need more help.

I have done that, and had followed the guide. Yet the notification email is
not going through
...

To clarify, the notification email for this form is not sending when the form is submitted or when the the "Order Approval" field has been filled?

I have tested a cloned version of your form and it seems the delivery details fields needs to be updated when editing the form.

After editing the delivery details, I was able to receive the confirmation email.

May we know which notification email is not sending?

Looking forward for your response.