Mfkey32 questions

Hello all!!

I am semi new to flipper and try to learn something new everyday. I saw the mfkey32 app and I had to download it. After downloading and looking online I’m a bit confused as to what it does. To my understanding you can scan the keys that a specific reader reads and emulate those keys through a card. What I don’t understand is they have a section that explains what to do if you don’t have a card but it does not say how to emulate those keys you get without a card? Also, do you have to use a card that was previously setup with said reader? For example if I wanted to get into my hotel room but I left the key inside, could i use an old Dave and busters NFC card and emulate the readers keys through the Dave and busters card? Or would I have to have an old hotel card from the same place then try and cracker the reader using the stored keys? Also I don’t understand what it means when it says to go to main menu → NFC → Saved → name → Detect reader. When I do that I don’t see a section called “detect reader” when looking at a specific NFC card. Does this “detect reader” option only pop up on specific cards or am I doing something wrong.

Last question: When I scan a mifare classic 1k card it has options such as “write to initial card” and “update initial card” after looking on Reddit I saw that they supposedly write the cards back to its original state? For example if I scan a Dave and busters card with the flipper then after playing a few games if I click write to initial card then it will make it so my points are back to where they were before I played the game. I don’t know if this example is correct or not. The update option confused me as well and I wasn’t able to form a complete understanding of it.

Thank you so much for your help!!