There is a roundabout way. You can press tab when placing the first network label to change the name to P11. In this way, you can continue to place the automatically named P12, P13..., and then select all labels. Use batch modification, right-click to find similar objects, and then click OK. Click the three dots in the lower right corner of the last line in the SCH Inspector that pops up, enter smart edit, and change all P1 to P1. That's it.