Volume group "vgubuntu" not found. My laptop won’t boot

Today, I rebooted my PC (a Dell G5 15) after a update from Ubuntu, you know, the kind of update that pops on the screen and asks you to reboot at the end to complete the update. Well, that’s what I did, and maybe I shouldn’t have. Now, I got this on my screen. (I have put red marks where I have executed the commands that were recommended above, for this thing to be a little clearer for you.) I don’t know what my latest version of Ubuntu that worked was. I tried to search for similar problems, but I couldn’t find anything that helped me in my case. I tried to select the “Advanced option for Ubuntu” when I hard-restarted my computer, but among the possibilities below, none seems to work. How can I fix my computer?