To create custom villager trades and professions in Minecraft APK Java Edition, you'll need to follow these steps:

Install Minecraft Forge: You'll need to have Minecraft Forge installed to be able to add custom trades to Minecraft. You can download Minecraft Forge from the official website.

Create a custom mod: Once you have Minecraft Forge installed, you'll need to create a custom mod to add your custom trades. You can use any Java IDE (Integrated Development Environment) to create your mod.

Define your custom trades: In your mod, you'll need to define your custom trades using the Minecraft data pack format. You can use Minecraft's built-in data pack generator to create a new data pack for your mod.

Add your custom trades to the game: Once you've defined your custom trades, you'll need to add them to the game. You can do this by placing your data pack in the Minecraft 'datapacks' folder.

Test your custom trades: After you've added your custom trades to the game, you'll need to test them to make sure they work as intended. You can do this by creating a new world and spawning a villager with your custom profession.

Overall, creating custom villager trades and professions in Minecraft Java Edition requires a bit of technical knowledge and skill, but it can be a fun way to add new content to the game.