This year Google announced that third-party hardware would be able to get in on the Developer Preview fun, with almost a dozen handsets getting Android P—assuming their owners were willing to be guinea pigs. Nokia allowed for 7 Plus owners to opt-in and try Android P, and now the consecutive update for the next preview is rolling out in a surprisingly timely manner. DP4/Beta 3 is landing via both image sideloading and OTA.
If you aren't already registered to participate in the developer builds, you can do so here. Also, Nokia notes that the update to Beta 3 (v3.110) will wipe all of your data, so make sure you've got anything you need to keep backed up ahead of time.
For those who haven't tried any of the previews before, you can learn about what you're getting into via Nokia's FAQ, and you can also take a look at our Developer Preview coverage of Android P, as most of the features we've discussed there should also be present.