Can not install on Linux Mint 20

I have not been able to get anywhere installing Arduino on Linux Mint 20. When I double click the install script install.sh
it simply shows the text of the file it does not run it. This has worked for me before. I do not understand why it does not work now. Can anyone assist me. I do not wish to be forced to use the Linux Mint repository to get a obsolete version.

Open a terminal at the Arduino IDE installation folder and run this command:

./install.sh

You should be able to configure your file browser software to offer to run scripts on double click, but it's easy enough to just run them from the terminal, plus then you can check the output to see if there was anything important.

One thing to note is that you don't even need to run that install.sh. You can simply run the "arduino" script you see in the installation folder and the Arduino IDE will start right up.