Intensity usually means load (% of 1RM) or effort (RPE/RIR). For hypertrophy: 60–80% 1RM, 0–3 RIR. For strength: heavier loads (80%+).
If you're interested in learning more about the program, I can try to provide more information or point you in the direction of resources that might be helpful. Intensity usually means load (% of 1RM) or effort (RPE/RIR)