If you have a voucher you will need to take it to a ticket booth at one of the parks to activate as I understand it. However...you can link your AP voucher to you
MDE and be able to make your FP+ selections 60 days out from your stay. That's what I did. I received my vouchers in mail then called Disney's IT (407-939-7765) and they very nicely and easily linked my APs to MDE so I can make advance FP+. I will them activate my passes when I get to Disney.
I'm just now waiting to find out when I will get my AP magic bands as I hear they come with a special AP thingy. I was told by Disney to give it a couple of weeks and they should show up on MDE. They haven't yet. I just have magic bands for my resort listed. I was given the AP hotline # (407-5650-7277) and will call them to find out about AP magic bands.