We purchased e tickets for annual passes through Sam's Club as we were able to get them at the old price even after Disney had announced their rather substantial price increase. I waited until just before my 60 day FP+ date to link them to my
MDE so I could make FP+, and it worked just fine. I think if you want a hard plastic ticket, you would have to get one once you arrived, but linking the e ticket to your MDE should let you get FP+ and get you into the parks.