TypeError: Cannot read properties of undefined (reading 'id') in vue 2 in background worker

I am trying to run background worker in my vue app to all api check some status from database. But I getting error call "TypeError: Cannot read properties of undefined (reading 'id')" from that background worker. Here is my vue component method:

created() {
    this.initWebWorker();
  },

method: {

 initWebWorker() {
          const worker = new Worker(staticAlias);
          worker.addEventListener('message', this.handleWorkerMessage);
          worker.postMessage({ isAdmin: this.isAdmin, event: this.event, programId: this.programId })

          this.worker = worker;
        },
        handleWorkerMessage(event) {
          console.log(event);
        },

},

beforeDestroy() {
    this.worker.removeEventListener('message', this.handleWorkerMessage);
    this.worker.terminate();
  },

and here is my background worker file:

self.addEventListener('message', async function (evt) {
  const { isAdmin, eventData } = evt.data;
  console.log(evt);
  if (!isAdmin) {
    try {
      const response = await fetch('check-event-status/' + eventData.id);
      const data = await response.json();

      if (localStorage.start_name === 'true' && data === 1) {
        self.postMessage({ redirect: true, programId: eventData.programId });
      }
    } catch (error) {
      console.error(error);
    }
  }

  setTimeout(() => {
    self.postMessage({ callApi: true });
  }, 1000);
});

Anyone have any idea about this? Is there any other way to do this?