Friction setting this up

So just install the app on two machine. Extremely confused by the numerous jump back and forth with the browser. At the end of it, I wanna add a member to my community. I would be tempted to copy paste the Npub here,

It says member user doesn't exist then I go dig deep into community settings to get an invite link I opened invite link in the other one. It opened the browser, it which opened the app, which tells me I'm not a member yet.

I'm so confused.

one thing is this these giant blocks in the middle that it's not clear that you expected to copy paste or type something in that yellow hollow space.

There this field, the sample data should be dimmer so we know it's a place to input something