Create Purchase Order for two different suppliers for the same item in SO

For a SO having an Item (qty = 10), I wish to source some qty from Supplier 1 and rest from Supplier 2
How can I create two Purchase orders for the same item with different suppliers?

I can create one PO for qty = 4 with supplier 1.
now when I create PO for pending qty = 6 for another supplier 2, I get alert that “PO is already existing”