uhh... you may guessed wrong. opera GX is only avaible on Win,Mac,Android and IOS. but theres a solution. Launch the terminal by pressing Ctrl + Alt + T. Install the Wine package using APT. The package name for the x86 version is wine32 and wine64 for x64 sudo apt-get install wine32. sudo apt-get install wine64. Enter y/yes when the installation prompt comes up. but if your not a scripter, make sure that you comuter has 32-bits or 64-bits. then do this steps. open terminal by pressing Ctrl+alt+T. then type "sudo apt update" and press ↵Enter, This will update the software repository.
For 64-bit systems: "sudo apt install wine64"
For 32-bit systems: "sudo apt install wine32"
If you are using Fedora or Redhat, install Wine using "kbd sudo dnf install winehq-stable". Type y to confirm the installation. When prompted to enter "y" or "n," press "y" to confirm the installation. Type in "winecfg" and press ↵ Enter. This creates a Windows home directory for Wine. Look for a confirmation message that says something like "created the configuration directory 'home/name/.wine'". If prompted to install any missing packages here, click Install in the prompt window and wait for the packages to install. Select a Windows version and click Apply. Click the "Windows Version" drop-down box at the bottom of the "Wine configuration" window, then click the version of Windows (e.g., Windows10) that you want to use. Then click Apply in the lower-right corner. Click OK. This button is at the bottom of the window. Clicking it closes the Window. then you can install any windows pograms (.EXE). install opera GX that you can find it on the downloads, and then right click "OperaGXsetup.exe", and then click "open with". then scroll untill you find "Winhlp32". then continue using the installation pogress. and then enjoy ur Opera GX! (this works well in Ubuntu)