There is a command “Toggle code” but no “Toggle code block” command. I use code blocks with three backticks much more frequently than single backtick code lines. Typing a backtick on a German keyboard is a pain.
Proposed solution
Have a command “Toggle code block” like “Toggle code” but with three backticks and not one. It should work with selected text and wrap it with backticks.
Current workaround (optional)
Cut the selected text, insert the 6 backticks with a template, go back, paste the code.
If you are willing to install the Templater plugin, you could try using this. It’s set for a css code block, but can be changed or duplicated to whatever is needed.