s2disk: Could not use the resume device (try swapon -a). Reason: No such device when setting hibernation

Question

I am trying setup hibernation using s2disk while using this answer on ubuntu 20.04 but am facing an error when testing it as below.

username@PC-Name:~$ sudo s2disk
s2disk: Could not use the resume device (try swapon -a). Reason: No such device

When I do swapon -s

username@PC-Name:~$ swapon -s
Filename                Type        Size    Used    Priority
/dev/nvme0n1p6                          partition   17942524    0   -2

and this is my disk