Compress box by fix box/relax until reaching target pressure

Hi friends & colleagues.
In my simulation: boundaries are periodic. I want to (isotropic) compress the box until reaches 100,000 Pa using fix box/relax.
However, when I ran the code, there was no warning or error, but the box volume and pressure did not change. I have read the documentation LIGGGHTS but I can not fix it.
I am not sure whether I missed something. So, do you have any comments and advice to fix this point? Thanks

#The part of my script is:
fix integr nve_group nve/sphere

compute pperatom all stress/atom
compute p all reduce update_on_run_end yes sum c_pperatom[1] c_pperatom[2] c_pperatom[3] c_pperatom[4] c_pperatom[5] c_pperatom[6]
variable press equal -(c_p[1]+c_p[2]+c_p[3])/(3*$(vol))

thermo_style custom step atoms ke vol v_press
thermo ${nstep}
thermo_modify lost warn norm no

#This part is trying to compress the box until reaching isotropic pressure = 100,000 Pa

fix preBoxcompr all box/relax iso 100000 vmax 0.0025

run 1000000