If the command palette is not opening then here are some trouble-shooting steps you can take. These may seem like "stupid questions", but they will often help you solve the problem.
If Turbo Admin has a short list of commands when you're on the front-end of the site, this is, currently, normal. It's scraping the menu items from the currently visible web page, and on the front-end of the site it only has some items in the toolbar to detect. In future I hope to "cache" menu items to allow more commands to be used on the front-end.
If Turbo Admin's "Login" command takes you to the wrong place, this is probably because you're admin is not on /wp-admin. For very good security reasons, WordPress doesn't broadcast the admin URL on the front-end of the site. And Turbo Admin has no way to detect it. So if you're site uses anything other than /wp-admin this command item won't work. I'm sorry. I did my best!