How to enter code in a post here so it looks structured?

edit

Where shall I drag it? When I drag it isn't it selected already?

Don't drag it anywhere - just use your mouse to highlight it. That is what librebel means by drag.

Thank you.

Thus I paste here, select it and push the button:

No command 'code' found, did you mean:
 Command 'cdde' from package 'cdde' (universe)
 Command 'node' from package 'nodejs-legacy' (universe)
 Command 'tcode' from package 'emboss' (universe)
 Command 'ode' from package 'plotutils' (universe)
 Command 'cde' from package 'cde' (universe)
 Command 'cobe' from package 'python-cobe' (universe)
code: command not found

Seems to work.