Do I need an app?

I feel a bit embarrassed to ask this. I bought a new Mac air and the salesman talked me into buying Norton 360 Platinum even though don’t totally understand it.
I followed the instructions and opened the website page and successfully activated my product code. I was wondering do I need to download an app? (if so, which one) to have on the laptop or is it just monitoring my email address behind the scenes?

Second question, It says across 5 devices. I have an iPad and an iPhone, all linked through Apple ID. Do I do anything special for them? ie install that app?

ok ty. I watched the videos but I never got a download button on my home page.

home page = meaning your Norton account - My Subscriptions page?
https://my.norton.com/extspa/account/subscriptions

and you reviewed Norton documentation [here]

I am feeling really frustrated. I have watched the videos, read the FAQ and still no help. I do not have a download button in the dashboard or ‘my subscriptions page’

Yes they ALL say the download button is on the dashboard or go to my subscriptions. I tried to post a screenshot as evidence but I wasn’t allowed to post it.

Correct. by Homepage I meant dashboard. I read you can go to my subscriptions and download the app if you were having trouble but I don’t have that option.
Which leads back to my original question. Do I even need an app for 360 platinum.
It says its monitoring my particulars and will contact my via email if they are breached?