# Forge Custom UI default hello world app with Custom UI does not work

**URL:** <https://community.developer.atlassian.com/t/forge-custom-ui-default-hello-world-app-with-custom-ui-does-not-work/60066>\
**Category:** Forge UI Kit and Custom UI\
**Tags:** hello-world, getting-started, forge-tunnel, jira-cloud, websockets\
**Created:** [July 21, 2022, 10:32pm UTC](https://community.developer.atlassian.com/t/forge-custom-ui-default-hello-world-app-with-custom-ui-does-not-work/60066 "2022-07-21T22:32:05Z")\
**Posts on this page:** 1\
**Showing post:** 6

<div class="post-metadata">

**Author:** ![JoshuaHwang](https://sea1.discourse-cdn.com/atlassiandeveloper/user_avatar/community.developer.atlassian.com/joshuahwang/32/44116_2.png) [@JoshuaHwang](https://community.developer.atlassian.com/u/JoshuaHwang)\
**Post date:** [July 28, 2022, 1:00am UTC](https://community.developer.atlassian.com/t/forge-custom-ui-default-hello-world-app-with-custom-ui-does-not-work/60066/6 "2022-07-28T01:00:08Z")

</div>

Hi again, the team mentions adding the following to your manifest. It appears firefox blocks websockets

```auto
permissions:
   external:
      fetch:
         client:
            - 'ws://localhost:3000'

```

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