Err: No event handlers were registered. This script does nothing. When trying to add a DO

name = "my-workers-file"
main = "src/worker.mjs"
compatibility_date = "2023-06-09"

[durable_objects]
bindings = [
  { name = "CHESS_GAME_NAMESPACE", class_name = "ChessGame", script_name = "my-workers-file" }
]
[[migrations]]
tag = "v1" 
new_classes = ["ChessGame"]

src
  -worker.mjs
  -ChessGame.mjs

export default {
    async fetch(request, env, context) {
        try {
          //Code 
        } catch (err) {
            //code
        }
    },
};

`export class ChessGame {
   constructor(state, env) {
     //initialization code
  }
  async fetch(request) {
   //code
   }
};

{
  "scripts": {
    "deploy": "wrangler deploy",
    "start": "wrangler dev"
  },
  "devDependencies": {
    "wrangler": "^3.0.0"
  },
}