I have been playing with this and got a little farther. I have an old SGS5 and got my kid set up there. Then I extracted the Family Link Manager APK (different than the Family Link APK).
Then:
- Installed the four APKs needed to install Google Play Store: https://xdaforums.com/amazon-fire/general/how-to-install-google-play-store-fire-t3486603
- Installed the Family Link Manager APK. I posted it here: https://drive.google.com/open?id=1eVmTXa1KqvZ_MV9tmYaZYYsd-2E1351C
- Launched Google Play Store
- Signed in as my child
- It asks which parent is setting up the device. I choose myself.
- Got a warning about Android 5 and not be able to control an apps permissions after approving.
- Then, a message that Family Link Manager needs to be installed. I already installed it at this point.
- Checking Info...
- It asks for a name for the Device
- Asks which installed apps should be blocked
- Then I get a screen that says, "Next, you'll activate Family Link Manager, which helps parents..."
After clicking next, I get a screen that says, "This profile manager is required for Google Accounts managed with Family Link." The only option is to click, "GOT IT." I then end up on the previous, "Next, you'll activate..." screen. If I click NEXT there, I see the same, "This profile manager is required..." screen. The process is now stuck in this loop. Does anyone have any idea what may be preventing the process from accessing the profile manager? Is it talking about the default Android profile manager? Has Amazon replaced that with their own?
One other thing: I cannot install the Family Link APK. It looks like it is going to, but then says "App not installed". Does anyone know if this is my whole problem? I have four kids, each with a Fire tablet. I am going to try this process on another one and see if I get closer.