How to delete a snapshot from a volume on a shelf SC 4020

Hello
The SС 4020 shelf has run out of space on SSD drives
We had a daily snapshot on volumes, but after the place ran out, we decided to remove the implementation of snapshots on some volumes

Several days have passed since snapshots were turned off on some accounts, and the snapshots have expired.

The question is, how do they delete themselves? Or do they need to be removed manually so that they don’t take up space?