Great question. Coinos atm provides only one NWC key so it could be used both ways, to receive and send sats, but NOT the same key simultaneously. That's why in the guide I use the address@coinos to receive and the Coinos NWC to receive.

supratic

In my case I use a wallet to receive and a different wallet for sending. The latter is coinos and I set up a budget there. 

Carresan

bitcoin_beginners

Finally attached wallets prior to November 5th

If using coinos to receive, why not also to send? Since it's already using NWC to receive in @supratic guide? 
Just curious about that detail.
Good post and great guide for folks too. Cheers.