How to treat PIH?

I get 2-3 pimples here and there, and they leave dark marks. My mom said they’d fade, but now I have quite a few marks on my face.

I asked AI about it, and it said it could be PIH and suggested this routine:
- Face wash (morning + night) → 0.5–2% salicylic acid based facewash
- Niacinamide serum 5% or 10% (morning)
- Salicylic acid 2% (night, alternate with azelaic acid)
- Azelaic acid 10% cream or gel (night)
- Benzoyl peroxide 2.5% or 5% (night)
- Sunscreen SPF 30+
- Moisturizer (morning + night)

I don’t wanna blindly trust AI. So, can someone recommend some good products (with brands and where to buy them) and a simple skincare routine?