This is the only legitimate method to turn a Java mod concept into a Bedrock .mcaddon without spending money.
Create a new folder named [ModName]_BP (Behavior Pack) and [ModName]_RP (Resource Pack). Bedrock separates logic and visuals, whereas Java often mixes them.
In the Resource Pack (RP) folder, create:
In the Behavior Pack (BP) folder, create:
If the JAR file is a "world save" (common in older versions or specific modpack launchers), conversion is highly successful and free.