MSSQL cant make backup because No such file or directory

[Cieptak]

Hi, I'm trying to make a backup of the "platnik" database.
The database is on MS SQL Server 2017.
The db-backup utility is located in Docker on Synology
The script connects to Windows Server 2012 and creates a backup file in the appropriate directory:

Unfortunately, when I try to copy this file to my Synology (DSM 7.1), I get the error:

md5sum: can't open 'mssql_platnik_192.168.16.110_20230503-125633.bak.zst': No such file or directory
md5sum: can't open 'mssql_platnik_192.168.16.110_20230503-125633.bak.zst': No such file or directory
stat: can't stat '/tmp/backups/mssql_platnik_192.168.16.110_20230503-125633.bak.zst': No such file or directory
date: can't stat '/tmp/backups/mssql_platnik_192.168.16.110_20230503-125633.bak.zst': No such file or directory
stat: can't stat '/tmp/backups/mssql_platnik_192.168.16.110_20230503-125633.bak.zst': No such file or directory
2023-05-03.12:56:35 [NOTICE] ** [db-backup] Backup of mssql_platnik_192.168.16.110_20230503-125633.bak.zst created with the size of bytes
mv: can't rename '/tmp/backups/mssql_platnik_192.168.16.110_20230503-125633.bak.zst': No such file or directory

what could be the cause of this? I will be very, very grateful for your help!
I am not a specialist, I will be happy to provide additional information if needed