The steps on installing you provided are hard to follow and in my case, doing what you said did not work (moved to applications but no dialogue came up) - maybe an installation video would be nice to have.
My Developer License has expired and I don't think I'd be renewing it for a while, you'd have to open the project on Xcode and install it manually.
Steps:
Download the project, and open it on Xcode.
Go to Signing & Capabilities, choose Team and Select Sign to Run Locally in Signing Certificate.
Build and Run the App.
(Optional) Go to Products under the Navigator and right click on DiscordX.app, click on Show in Finder. Copy/Cut - Paste in Applications folder and it should be easier to launch next time.
The steps on installing you provided are hard to follow and in my case, doing what you said did not work (moved to applications but no dialogue came up) - maybe an installation video would be nice to have.