Pacote Debian para Ubuntu: Basta baixar, clicar e instalar.

• GitHubDesktop-linux-amd64-3.3.3-linux2.deb
  87.9 MB 2023-10-08T18:10:17Z
• ========================================

• GitHubDesktop-linux-aarch64-3.3.3-linux2.rpm
  93.7 MB 2023-10-08T18:10:17Z
• GitHubDesktop-linux-aarch64-3.3.3-linux2.rpm.sha256
  64 Bytes 2023-10-08T18:10:17Z
• GitHubDesktop-linux-amd64-3.3.3-linux2.deb
  87.9 MB 2023-10-08T18:10:17Z
• GitHubDesktop-linux-amd64-3.3.3-linux2.deb.sha256
  64 Bytes 2023-10-08T18:10:17Z
• GitHubDesktop-linux-arm64-3.3.3-linux2.AppImage
  122 MB 2023-10-08T18:10:17Z
• GitHubDesktop-linux-arm64-3.3.3-linux2.AppImage.sha256
  64 Bytes 2023-10-08T18:10:17Z
• GitHubDesktop-linux-arm64-3.3.3-linux2.deb
  83.3 MB 2023-10-08T18:10:17Z
• GitHubDesktop-linux-arm64-3.3.3-linux2.deb.sha256
  64 Bytes 2023-10-08T18:10:17Z
• GitHubDesktop-linux-armhf-3.3.3-linux2.deb
  80.2 MB 2023-10-08T18:10:17Z
• GitHubDesktop-linux-armhf-3.3.3-linux2.deb.sha256
  64 Bytes 2023-10-08T18:10:17Z
• GitHubDesktop-linux-armv7l-3.3.3-linux2.AppImage
  109 MB 2023-10-08T18:10:17Z
• GitHubDesktop-linux-armv7l-3.3.3-linux2.AppImage.sha256
  64 Bytes 2023-10-08T18:10:17Z
• GitHubDesktop-linux-armv7l-3.3.3-linux2.rpm
  89.1 MB 2023-10-08T18:10:16Z
• GitHubDesktop-linux-armv7l-3.3.3-linux2.rpm.sha256
  64 Bytes 2023-10-08T18:10:17Z
• GitHubDesktop-linux-x86_64-3.3.3-linux2.AppImage
  123 MB 2023-10-08T18:10:16Z
• GitHubDesktop-linux-x86_64-3.3.3-linux2.AppImage.sha256
  64 Bytes 2023-10-08T18:10:17Z
• GitHubDesktop-linux-x86_64-3.3.3-linux2.rpm
  102 MB 2023-10-08T18:10:17Z
• GitHubDesktop-linux-x86_64-3.3.3-linux2.rpm.sha256
  64 Bytes 2023-10-08T18:10:17Z
• Source code (zip)
  2023-10-08T17:33:18Z

Fonte: https://github.com/shiftkey/desktop/releases/tag/release-2.0.4-linux1