Recover files on RAID5 with Extundelete?

So I've done a lot of reading and know this is my fault! However I still think there is a chance I can recover some files, so just wanted to ask here as a last resort.

I have a 4 disk (4TB x 4) setup in RAID 5.

I'm just trying to understand how this is seen as a raw device, it looks like the partition/device that contains the shares is /dev/md127 ?

cat /proc/mdstat
Personalities : [raid0] [raid1] [raid10] [raid6] [raid5] [raid4] 
md127 : active raid5 sdb3[0] sdc3[3] sdd3[2] sda3[1]
      11706506496 blocks super 1.2 level 5, 64k chunk, algorithm 2 [4/4] [UUUU]
      
md1 : active raid6 sda2[0] sdd2[3] sdc2[2] sdb2[1]
      1047424 blocks super 1.2 level 6, 64k chunk, algorithm 2 [4/4] [UUUU]
      
md0 : active raid1 sda1[0] sdd1[3] sdc1[2] sdb1[1]
      4190208 blocks super 1.2 [4/4] [UUUU]

The only option is to run extundelete on the NAS itself because I don't have a drive large enough to clone this array. What device should I be trying to run this on, and is it possible to unmount a share temporarily, maybe that will help?