problem faced when active openfoam

I typed the word on my command-line window, is that right? I installed openfoam v9. When I active it, I don't understand the word for openfoam v9 avoid needing an editor. Does that mean that I don't need to type the sudo command. If it is why does Ubuntu show that on picture 2? If not, how can I solve it because the website said one time only? Does that mean I just have one chance to do that?

The instructions say to enter that text in the command line rather than opening a text editor in order to edit your .bashrc file.

The >> redirects the output of the echo’d command to the end of the .bashrc file - ie it appends the text to the end of the file, so you don’t need to edit the file directly with a text editor.

Do type it carefully - for example if you use > instead of >> you will end up replacing your .bashrc file with that line of text!

So step 1 is to enter the text to edit your .bashrc file via the command line; step 2 tells the shell to read the .bashrc file to ‘activate’ the changes; step 3 confirms it has all worked.