Converting a .jar file directly into a .mcaddon is complex because Java Edition mods (JAR) and Bedrock Edition add-ons (MCADDON) use fundamentally different coding languages and engines. However, you can use specialized porting tools or manual repackaging depending on what is inside the file. Option 1: Using Automated Porting Tools (Recommended)
mc-validator.exe MyConvertedAddon/
Java uses .json models (for blocks/items) but with a different syntax than Bedrock. how+to+convert+jar+to+mcaddon+verified
min_engine_version in the manifest..mcaddon to MCPEDL or CurseForge Bedrock. Wait for 50 five-star reviews. Congratulations, you are now peer verified.