generally speaking options are:

— AHA acids — lotions/toners/serums with lactic or glycolic acid (you will need moisturizer with toners and serums);

— BHA acid — products with salicylic acid;

— retinoids; creams and serums with retinol/retinal or if you can get it tretinoin (probably the best option but quite expensive when you have to use it on large area);

— Urea — like, foot balms or keratolytic creams (less than 10-20% probably won't do shit);

— topical steroids may show impressive results but they are only suitable for short-term use because withdrawal syndrome is no fun (and unlike tretinoin I wouldn't try to get them without prescription and use without supervision).

Some people have success with additional physical exfoliation with scrubs for others however it worsen the situation.

What will help you specifically is a trial and error, the same product can be a miracle cure for one person and do absolutely nothing or even have negative impact for others.

Shea butter or vaseline as a final step to lock moisture can be beneficial too even though they don't dissolve keratin plugs because skin with KP tends to be dry and dehydrated and dryness and dehydration worsen KP.