Getting Error: Timed out waiting for initial response from parent after 10000ms when trying to register an extension for Admin UI SDK

[AndreiDu]

I'm trying to integrate Admin UI SDK into our Adobe Commerce instance while following the official docs.

While trying to test the integration using the provided sample app, I'm running into the following issue:

As a result, I don't see the sample app in the admin section of Adobe Commerce.

This is the code that registers the extension, it's from the sample app:

/*
 * Copyright 2022 Adobe
 * All Rights Reserved.
 *
 * NOTICE: All information contained herein is, and remains
 * the property of Adobe and its suppliers, if any. The intellectual
 * and technical concepts contained herein are proprietary to Adobe
 * and its suppliers and are protected by all applicable intellectual
 * property laws, including trade secret and copyright laws.
 * Dissemination of this information or reproduction of this material
 * is strictly forbidden unless prior written permission is obtained
 * from Adobe.
 */
import { register } from '@adobe/uix-guest'
import { extensionId } from './Constants'
import { MainPage } from './MainPage'

export default function ExtensionRegistration(props) {
  init().catch(console.error)
  return <MainPage runtime={props.runtime} ims={props.ims} />
}

const init = async () => {
  await register({
    id: extensionId,
    methods: {
      menu: {
        getItems() {
          return [
            {
              id: `${extensionId}::first`,
              title: 'First App on App Builder',
              parent: `${extensionId}::apps`,
              sortOrder: 1
            },
            {
              id: `${extensionId}::apps`,
              title: 'Apps',
              isSection: true
            }
          ]
        }
      },
      page: {
        getTitle() {
          return 'First App on App Builder'
        }
      },
      product: {
        getMassActions() {
          return [
            {
              actionId: `${extensionId}::first-mass-action`,
              label: 'First App Mass Action',
              type: `${extensionId}.first-mass-action`,
              confirm: {
                title: 'First App Mass Action',
                message: 'Are you sure your want to proceed with First App Mass Action on selected products?'
              },
              path: '#/first-mass-action',
              productSelectLimit: 1
            },
            {
              actionId: `${extensionId}::another-first-mass-action`,
              label: 'Another Mass Action',
              type: `${extensionId}.another-mass-action`,
              path: '#/another-mass-action'
            }
          ]
        },
        getGridColumns() {
          return {
            data:{
              meshId:'',
              apiKey: ''
            },
            properties:[
              {
                label: 'App Column',
                columnId: 'first_column',
                type: 'string',
                align: 'left'
              }
            ]
          }
        }
      },
      order: {
        getGridColumns() {
          return {
            data:{
              meshId:'',
              apiKey: ''
            },
            properties:[
              {
                label: 'First App Column',
                columnId: 'first_column',
                type: 'string',
                align: 'left'
              },
              {
                label: 'Second App Column',
                columnId: 'second_column',
                type: 'integer',
                align: 'left'
              },
              {
                label: 'Third App Column',
                columnId: 'third_column',
                type: 'date',
                align: 'left'
              }
            ]
          }
        },
        getMassActions() {
          return [
            {
              actionId: `${extensionId}::order-first-mass-action`,
              label: 'First App Mass Action',
              type: `${extensionId}.order-first-mass-action`,
              confirm: {
                title: 'First App Mass Action',
                message: 'Are you sure your want to proceed with First App Mass Action on selected orders?'
              },
              path: '#/first-mass-action',
              orderSelectLimit: 1
            },
            {
              actionId: `${extensionId}::second-mass-action`,
              label: 'Second Mass Action',
              type: `${extensionId}.second-mass-action`,
              path: '#/another-mass-action'
            }
          ]
        },
        getOrderViewButtons() {
          return [
            {
              buttonId: `${extensionId}::delete-order`,
              label: 'Delete',
              confirm: {
                message: 'Are you sure your want to proceed to delete order?'
              },
              path: '#/delete-order',
              class: 'custom',
              level: 0,
              sortOrder: 80
            },
            {
              buttonId: `${extensionId}::create-return`,
              label: 'Create Return',
              path: '#/create-return',
              class: 'custom',
              level: 0,
              sortOrder: 80
            }
          ]
        }
      }
    }
  })
}