document numbering

Hello,

I have a question regarding the document numbering for purchase agreements.

Currently, when I create either a Blanket Purchase Agreement or a Contract Purchase Agreement, the system generates numbers using the same prefix, like:
• Contract Purchase Agreement → CON-250001
• Blanket Purchase Agreement → CON-250002

I would like to configure the system so that:
• Contract Purchase Agreements use the prefix CON-********
• Blanket Purchase Agreements use the prefix BLK-********