I'll help you add the Project ID in your bill template, @Lumiousacct.

The option to create a bill template that you can use when paying a vendor is unavailable in QuickBooks Online (QBO). However, you can use the Memo section to add the Project ID manually. 

If you're referring to a bill template that you can use when sending an invoice, we can customize your invoice and add another custom field for Project ID. Let me show you how:

1. Click the Gear icon and select Custom Form Styles.
2. Choose the invoice template that you wanted to edit, then go to the Content section.
3. Click the Pencil icon on the upper section of the invoice template.
4. Select the Custom field in the lower section of the page.
5. Enter Project ID, then make sure the box is selected.
6. Click Done.

Once done, you can now create an invoice and manually add the Project ID details. You can also open an Invoice List report and customize it to view the Project ID. Here's how:

1. Go to Reports and search for the Invoice List report.
2. Click Customize and select Filter.
3. Check the Project ID box and click Run report.

That's it! Please let me know if there's anything else I can do to be of assistance. Stay safe.