Your goal is to get the file into a readable format like this, modify the numbers, and then save it back.
Editing an .es3 save file—created by the asset for Unity—depends on whether the developer has enabled encryption. By default, these files are stored in a JSON format and are human-readable, but many games use AES encryption to prevent tampering. Method 1: Direct Text Editing (Unencrypted Files) how to edit es3 save file
Use to search for the value you want to change (e.g., "gold", "health", "level"). Your goal is to get the file into