job to duplicate backup sets

Click on your backup job and then click on the Add Stage button on the right sub-pane.  This will give you the option to duplicate to tape.

Clicking on the Add Stage doesn't give me the option of duplicating it to tape.  It says I could duplicate it to disk or convert it to VM.

Proceed with ‘Add Stage’ button as pkh has suggested and then select ‘Duplicate to Disk’ option. It will add another stage named ‘Duplicate’ to your backup solution

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Now 'Edit' it and target the backup to your tape drive from ‘storage’ section. It will list all devices you can target the backup to.