I was trying to do it but can’t see the Cart in profile mode on my phone. I see the cart in landscape mode.

Also, I don’t have an account yet. Is there a way to “sign in” with Lightning? Or does it require me to get a Nostr plugin running? 

 You can log in with a Nostr extension like nostrconnect or Nos2x. 

 Cool. Will try it out later tonight. Is there a developing consensus on which one of these is best? Using Orion browser which lets me choose either Chrome or Firefox extensions. 

 Both are great. I use nostrconnect just because I like the UX