Approve purchase order - SAP Fiori App

[MaximoSanchez]

Hello experts, a pleasure to talk to you.
Today I have the following query:
I need to implement Fiori : Approve purchase order application (App ID: F0402A) on my SAP S/4 HANA Cloud Private system. (https://fioriappslibrary.hana.ondemand.com/sap/fix/externalViewer/#/detail/Apps('F0402A')/S32)
I've searched a lot but I'm just meager with the information I got, so I would like to know if someone could help me to find my way to implement this application.
My doubts are:
1) What is My inbox? and how does it relate to Approve purchase order.
2) Is there any demo video to see how the application works?
3) I only have to install the Front-End Components and the Back-end Components, and the application will start working?
4) Can I only implement the Approve purchase order application or should I implement some other application together with this one for its correct operation?

Of course I thank anyone who can help me, because it is a big problem I need to solve. Thank you very much in advance to everyone!

Regards, Max.

[Jocelyn_Dart · Accepted solution]

HI Maximo

Believe you are looking for this SAP Note:

2371741 - Additional Information for approval of Purchasing Documents within S/4HANA. 

Next time you need to ask a question try using the tag: SAP Fiori for SAP S/4HANA

That's the best tag to use for queries about SAP Fiori apps in SAP S/4HANA. 

Best

Jocelyn