@Zexi Liu you need to use skywater models as provided by open_pdks. Do not manually install skywater-pdk, use open_pdks, which also fetches skywater-pdk and does lot of patches and corrections. After these correction the pnp subcircuit is a 3 terminal device:
...
...
* SKY130 Spice File.
.param sky130_fd_pr__pnp_05v5_W0p68L0p68__bf_slope = 0.0
.param sky130_fd_pr__pnp_05v5_W0p68L0p68__is_slope = 0.0
* statistics {
* mismatch {
* vary sky130_fd_pr__pnp_05v5_W0p68L0p68__bf_slope dist=gauss std=0.05537
* vary sky130_fd_pr__pnp_05v5_W0p68L0p68__is_slope dist=gauss std=0.01662
* }
* }
.subckt sky130_fd_pr__pnp_05v5_W0p68L0p68 Collector Base Emitter
+
.param mult = 1.0
...
...