why doesn't my Custom UI dashboard gadget show in gadgets

[Wessel de Jongh]

I started using forge to create some own apps in Jira. Particularly Jira dashboard widgets with custom UI. I want to have a simple widget with an iframe where you put in a URL, and it will show the iframe. I believe due to protection you cannot achieve this with the UI kit (not all URL's)

I have created the app with forge. Then when I deploy and install it on my website, it just isn't there with the gadgets. Just to try, I've tried with UI kit and it does work.

To get to specifics, when I create the app I use "jira-dashboard-gadget-custom-ui". The app is deployed and installed, and it is added in the developer console. I've also tried deleting the app, uninstalling, re-creating and re-installing (no changes to the code). At first, I thought it might be because it is custom UI and there is nothing coded yet, but the default does include some kind of code for the edit and view part.

I can also find documentation for custom UI apps and dashboard widgets with UI kit but never dashboard widgets with custom UI documentation, which makes this all the harder. 

Is there someone with knowledge about this that could help me? Or maybe some point out some documentation that I missed or that could help me. Right now I am just stuck not being able to develop anything.

Hope someone is able to help