Lately, Microsoft has been using firewalls by asking for license when Minecraft PE from an external source is downloaded. This happens for 1.2.6.2 frequently, which is the last version which doesn’t disallow a player to play online from playing online if it is downloaded from an external source. However, there is still a way to play with your friends without losing the classic element of Minecraft with your friends.
Minecraft PE
https://apknode.com/app/com.mojang.minecraftpe/1.1.5.1_paid.html
1.1.5.1 is an old version of Minecraft that I found in my old SD card. This works pretty fine and at most you will miss would be stained coloured glasses. This has most of the redstone functions, beacon stuff, combat functions, etc. You can download this, and even in an old machine like LG G Pro Lite, in-built APK installer will safely install this to your phone.
Xbox App
https://play.google.com/store/apps/details?id=com.microsoft.xboxone.smartglass&hl=en_IN
To sign in the game, you need the Xbox app most of the time. I haven’t tried signing in without the app, but you’re up to the test. The Xbox app doesn’t have problems with any version at all. In the latest versions, Xbox app will refuse to open. In 1.2.6.2, MCPE won’t open to begin with. So that’s why I use 1.1.5.1
For PC
There are two simulators that, so far I’ve tried, support APKs, MCPE downloaded from external sources, etc.
BlueStacks: https://www.bluestacks.com/
Tencent Gaming Buddy: https://tgb.qq.com/en/games/pubg.html
There’s not much disparity when it comes to installation. Both TGB and BS4 have the option to install APK. The difference is that BS4 recognises a keyboard, whereas TGB has the option to mapping keys on the screen, so you’ll probably have to mark and map WASD if it doesn’t recognise keyboard.
How to install APK in Tencent Gaming Buddy: https://techjourney.net/how-to-install-app-apk-in-tencent-gaming-buddy-android-emulator/
There are some problems with TGB, apparently you have to switch the language to Chinese to get the option to install APKs and whatnot, so here’s a link to deal with that.