Ubuntu 20.04 can't hibernate

I am still getting the message 'Failed to hibernate system via logind: Sleep verb "hibernate" not supported' when I use the command 'sudo systemctl hibernate' even after following the instructions found here: How to hibernate with swapfile. I am running Ubuntu 20.04 on my Thinkpad L470 with 16GB of RAM. Following the instructions in the link above, I created a /swapfile corresponding to the size of my RAM. If there is anything else I need to do please help.

Do the instructions here work? How to enable hibernate option in Ubuntu 20.04?

I assume you have a swap partition ready to use. (If you have a swap file you cannot hibernate) Install pm-utils and hibernate:

bash sudo apt install pm-utils hibernate

Then:

bash cat /sys/power/state

You should see:

none freeze mem disk

Then run:

bash grep swap /etc/fstab

Copy the UUID value. You will need it later. Then run:

bash sudo nano /etc/default/grub

(or your favourite editor if not nano). Change the line that says

none GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

so that it instead says:

resume=UUID=YOUR_VALUE" ```

Then, after saving the file and quitting the text editor, run:

```bash sudo update-grub ```

To test it, run:

```bash sudo systemctl hibernate ```

Right now no GNOME extension is working to have the hibernate option
back in the system menu.

Tested on Ubuntu 20.04 Kernel 5.4.0-31 on my Lenovo Thinkpad X1
Carbon.