You can't because pocketmine needs to be in a 64bits device and most of smartphones are 32bits, please search before asking here, this question has been posted more than 100 times.. https://forums.pmmp.io/search/9516503/?q=android&o=date&c[node]=18
What phone do you have? Some newMost newer phones are 64 bit. I have to warn you though, running PocketMine won't be as easy as just installing an app.
Hello, I never tested it but it seems like it works. https://forums.pmmp.io/threads/pocketmine-mp-for-android-64-bit.5226/ Github for the app https://github.com/Frago9876543210/PocketMine-MP-Android/releases For 64 bits android smartphone
Then please, contact the author and try to talk with him. He should add a plugin section too like the PocketMine-MP app on android.
look at github.com/termux for cross compile php for your device ONLY FOR 64-BIT after you cross compiled it and test it with php -v at Termux copy phar into your device and Code: php PocketMine-MP.phar also Termux has a APT repo check it