Countly-server for flutter push notification?

[NTMS2017]

Hi,

I am new so please bare with me.

First I install on my macOS (big sur) VmwareFusion Play free edition. Than on top it I install Ubuntu Desktop 20.04LTS.

Now before I install Countly-server (only for push notification) in System-Requirements page talks about installing NodeJS 14.x and MongoDB 4.4.x.

(Question-1): Should I install both NodeJS 14.x and MongoDB 4.4.x or just one? Does Countly-server uses both NodeJS 14.x and MongoDB 4.4.x and why?

(Question-2): Due to low resources I need to use Countly-server push notification only. So Is there and option to install only Push Notification module?

(Question-3): Because I want to test Countly-server push notification (for my flutter mobile app) on my MacBook, can I test push notification on my flutter app development using Countly-server community edition?

Thanks