NetVault Backup has no plugin to support backing up Progress Databases.
To use NetVault Backup to protect Progress Database servers, first use the Progress native backup and restore tools probkup and prorest.
Use probkup to backup the database to a filesystem location, and then use Netvault Backup to backup this file/s to NetVault managed tape.
At restore time, restore the file/s from NetVault managed tape to filesystem, and use prorest to recover the databases.