The answer I received was to use the setText function.
Below is the code that worked.

 self.ui.bill_street_1.setText(f'{self.customer_rec[2]}')
        self.ui.bill_street_2.setText(f'{self.customer_rec[3]}')
        self.ui.bill_city.setText(f'{self.customer_rec[4]}')
        self.ui.bill_state.setText(f'{self.customer_rec[5]}')
        self.ui.bill_zip.setText(f'{self.customer_rec[6]}')
        self.ui.bill_zip_plus.setText(f'{self.customer_rec[7]}')
        self.ui.ship_street_1.setText(f'{self.customer_rec[8]}')
        self.ui.ship_street_2.setText(f'{self.customer_rec[9]}')
        self.ui.ship_city.setText(f'{self.customer_rec[10]}')
        self.ui.ship_state.setText(f'{self.customer_rec[11]}')
        self.ui.ship_zip.setText(f'{self.customer_rec[12]}')
        self.ui.ship_zip_plus.setText(f'{self.customer_rec[13]}')
        self.ui.last_order.setText(f'{self.customer_rec[14]}')
        self.ui.terms.setText(f'{self.customer_rec[15]}')