How do I get value from CloudDB in background if I pressed 'back' button to leave?

I tried to receive message by CloudDB
when I close my app, so I search solution in here.
Someone mentioned 'TaifunTools' so I downloaded it.
I import it to my app and tried to receive message when I pressed 'back' button to leave, but noting happened.

I wanted to make an app like WhatsApp. An app can send message, receive message etc.
ACNHFreeMaterial(001001004a,V.1.1.4α).aia (236.2 KB)

Welcome there,

Please post a screenshot of your relevant blocks or export your AIA file here to get help.

It is very simple for making
If you want I'll make one for you
Just DM me