Earlier last month, Asus rolled out the Android Pie update for the Zenfone Max (M2) in India, sporting the model number ZB632KL. Now, the company has expanded the rollout of the latest version of Android globally for the 2018 smartphone for all units, bearing the ZB633KL moniker.
The firmware carries version number 16.2018.1905.42 and bumps up the Android security patch level on the smartphone to May 2019.
Asus says the update is rolled out in batches, and it may take "some days" before you get an update prompt on your smartphone. If you can't wait for that, you can try pulling the update manually by heading over to the Settings > System > System updates menu.