How to extend LVM2 partition while keeping existing files

Question

OS: Ubuntu 20.04 server edition

I'm attempting to adjust my Proxmox installation that I copied from my 120GB SSD to my 500GB SSD. However, fdisk is complaining about the 'GPT PMBR size mismatch'. I'd also like to use more than the 120GBs that the partition currently expands. I used the following command to clone my disk. dd if=/dev/sdd of=/dev/sda bs=64K conv=noerror,sync

My fdisk -l is

GPT PMBR size mismatch (234441647 != 976773167) will be corrected by write.
The backup GPT table is not on the end of the device. This problem will be corrected by write.
Disk /dev/sda: 465.78 GiB, 500107862016 bytes, 976773168 sectors
Disk model: Samsung SSD 860
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: E3F8FE62-0684-438A-AD48-13619521C03B

Device       Start       End   Sectors   Size Type
/dev/sda1       34      2047      2014  1007K BIOS boot
/dev/sda2     2048   1050623   1048576   512M EFI System
/dev/sda3  1050624 234441614 233390991 111.3G Linux LVM

vgdisplay gives

  --- Volume group ---
  VG Name               pve
  System ID
  Format                lvm2
  Metadata Areas        1
  Metadata Sequence No  20
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                7
  Open LV               0
  Max PV                0
  Cur PV                1
  Act PV                1
  VG Size               <111.29 GiB
  PE Size               4.00 MiB
  Total PE              28489
  Alloc PE / Size       24938 / 97.41 GiB
  Free  PE / Size       3551 / 13.87 GiB
  VG UUID               n7Lsrx-5p8k-ti6F-xJKR-CBrN-6vnx-7Rcx6H

I've tried using lvextend, but everytime it tells me it's an invalid path. How the hell do I extend this partition?