linux – Ubuntu 20 Extend LVM

I did a fresh install of Ubuntu 20.04. I have 3 drives on the server. SDA=1.8TB, SDB=1.8TB, SDC=6.4TB. The OS is installed on SDA. When execute a df-h command I appear to be missing some space on SDA. It’s not adding up to 1.8TB. It seems the OS install did not allocate the lvm buntu–vg-ubuntu–lv to use the full amount of space. There is about 1TB missing. How do I extend the LVM and reclaim that space? or see where it’s being used?

$ df-h
Filesystem                         Size  Used Avail Use% Mounted on
udev                               126G     0  126G   0% /dev
tmpfs                               26G  2.4M   26G   1% /run
/dev/mapper/ubuntu--vg-ubuntu--lv  196G   11G  176G   6% /
tmpfs                              126G     0  126G   0% /dev/shm
tmpfs                              5.0M     0  5.0M   0% /run/lock
tmpfs                              126G     0  126G   0% /sys/fs/cgroup
/dev/sda2                          976M  105M  805M  12% /boot
/dev/sda1                          511M  7.9M  504M   2% /boot/efi
/dev/sdb                           1.8T   77M  1.7T   1% /drives/raid10-1
/dev/sdc                           6.4T   89M  6.0T   1% /drives/raid5-1
/dev/loop0                          30M   30M     0 100% /snap/snapd/8542
/dev/loop1                          55M   55M     0 100% /snap/core18/1880
/dev/loop2                          72M   72M     0 100% /snap/lxd/16099
tmpfs                               26G     0   26G   0% /run/user/1000


$ lsblk
NAME                      MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
loop0                       7:0    0 29.9M  1 loop /snap/snapd/8542
loop1                       7:1    0   55M  1 loop /snap/core18/1880
loop2                       7:2    0 71.3M  1 loop /snap/lxd/16099
sda                         8:0    0  1.8T  0 disk
├─sda1                      8:1    0  512M  0 part /boot/efi
├─sda2                      8:2    0    1G  0 part /boot
└─sda3                      8:3    0  1.8T  0 part
  └─ubuntu--vg-ubuntu--lv 253:0    0  200G  0 lvm  /
sdb                         8:16   0  1.8T  0 disk /drives/raid10-1
sdc                         8:32   0  6.4T  0 disk /drives/raid5-1

Thanks in advance.