Data recovery of Synology HDD in btrfs on Windows

I have Synology DS418play NAS with couple of HDDs in it.

Main data is in RAID1, and I had one more disc with movies and some music shows on it.

It’s a Seagate IronWolf 10 TB (ST10000VN0004). From time to time it was crashing and Synology switched it to Read Only mode, but switching it back to Read/Write mode usually fixed the issue.

Anyways, few days ago, it crashed again, but switching to Read/Write failed this time. I restarted NAS and it said:

Severe file system errors have occurred because of drive errors in this storage pool. To rescue your data, please sign in to your Synology Account and submit a technical support ticket.

I tried contacting Synology support, but they were unable to fix the disc, saying:

We also tried our rescue tool, Btrfs Restore, but due to a serious hard drive failure, the data could not be retrieved.