Using Ubuntu 22.04LTS on my proxmox system.

Added 70GB to my 30GB partition for a total of 100GB – used the Proxmox GUI to handle this change.

Logged into the Ubuntu VM (CLI Only)
Verify my disk (sda) shows 100GB and my partition (sda3) shows 30GB
lsblk

Verify /dev/mapper with df -h (needed for lvextend below, see example)

FDISK
fdisk /dev/sda
p
d
3
n
3
w

p to verify the partitions, although this also shows in lsblk. d to delete, selecting 3. n for new partition, 3, start and end are defaults to fill the disk. w to write the changes. MAKE SURE YOU DON’T SELECT TO DELETE THE LVM SIGNATURE OTHERWISE YOUR DATA MAY BE LOST.

Resize the partition table in LVM
pvresize /dev/sda3

Extend the logical volume in LVM
lvextend -l +100%FREE /dev/mapper/ubuntu–vg-ubuntu–lv

Resize the filesystem for Ubuntu
resize2fs /dev/mapper/ubuntu–vg-ubuntu–lv