Hi 2morses,

You can create and send the purchase order to your supplier through email. Let me walk you through on how to send the form.

1. Click Expenses on the left menu.
2. Go to the Expenses tab.
3. Select the purchase order that you want to send.
4. Under the Action column, click Send.
5. Provide the supplier's email address, click Send.

Also, since the ability to remove the Approved by option is unavailable, you can leave it as blank. Once the PO is approved, you can manually send another copy to your supplier with your name beside Approved by.

I'll also make sure to pass this along to our product team to let them know of your business needs. 

Here's an article for more information about creating purchase order: Create Purchase Orders in QuickBooks Online.

You'll want your purchase order to be copied to the bill. Just simply open the PO and click Copy to Bill besides the amount. For future reference, you can run reports in QBO to know the total outstanding bill amount: Run Reports in QuickBooks Online.

Let me know if you have any additional questions. I'll be one post away if you need help.