You need to edit "
/etc/initramfs-tools/conf.d/resume"
file to provide an UUID of a swap partition, or a path,
in case of LVM, to a swap partition and run:
# update-initramfs -u
Example for traditional disk partitioning scheme:
$ cat /etc/fstab | grep -iE "swap"
UUID=e990fa6d-3f82-4d65-b6a1-542e240718fc none swap
sw 0 0
$ cat /etc/initramfs-tools/conf.d/resume
RESUME=UUID=e990fa6d-3f82-4d65-b6a1-542e240718fc
Example for LVM partitioning scheme:
$ cat /etc/fstab | grep -iE "swap"
/dev/vg0-nvme/lv1-swap none swap sw 0 0
$ cat /etc/initramfs-tools/conf.d/resume
RESUME=/dev/vg0-nvme/lv1-swap