Clarification for the shiny Koraidon and Miraidon event?

This will be the first time in my life I've been able to attend an in person pokemon distribution, so I wanted some clarification.

I've been going over the announcement page for the shiny Koraidon and Miraidon event and am having trouble understanding a few things about how exactly distribution works.

From what I understand, I must arrive in person to a GameStop and ask the employee at the desk for my code, and the code will work in either Scarlet or Violet and each game gives the opposite box legendary (miraidon for scarlet, Koraidon for violet).

I have, however been hearing conflicting information concerning having to do more than just show up and ask.

So here's my questions

1- do I need to have my switch with me to show that I own the game, the site doesn't say.

2- do I HAVE to show them my scarlet icon in pokemon home

3- while I do have mobile hotspot on my phone I shouldn't have an issue, how would one even be able to present that (disregard if GameStop provides a wifi hotspot themselves)

4- is the code ACTUALLY version dependent, as in, do I HAVE to get miraidon, as I only really want Koraidon of I have to chose between the 2. I could always just trade later but I'd like to know just in case.

Thanks for your time and answers