After creating bookings, you can set a singular supplier to multiple bookings to send off.
How to set a supplier for multiple bookings
Navigate to Bookings
Click on the Bookings Board tab
Select the Set Supplier button on the top right-hand corner of the bookings board.
Choose the Supplier in the top drop-down menu.
You can pick the bookings you want to apply to the supplier or just click the Select All button.
Press Set Supplier
Once a supplier has been set for a booking, they will be default hidden from this section and be shown within the supplier booking Tab. Setting a supplier does not send off the booking to them yet.