When ran Backup API, it doesn't create backup.properties file in backup path

 
We are trying to backup indexes in Prod. It created snapshots in mentioned location. But it didn't create backup.properties, zk_backup files in that location.
So when we use restore api, we are not able to restore, It failed with exception that "No backup.properties file"
We need help to know why backup.properties file is not created. Below is the api we are using for backup.

http://username:password@hostname:port/solr/admin/collections?action=BACKUP&name=$newBackupName&collection=$myCollectionName&location=/opt/epricer-solr-backup/DR