Vetericyn Plus Dog Wound Care Hydrogel Spray | Healing Aid and Wound Protectant, Sprayable Gel to Relieve Dog Itchy Skin, Safe for All Animals. 3 Ounces

That is a cat zit. The gunk in the ones on their chins often gets really hard. Try using hypochlorous acid wound care gel on it, it's worked great for me cats. There is also a spray, but I like the gel spray better because I can spray three or four squirts on my fingertips and have time to get it to the cat's chin. Trying to spray anything directly on cats freaks them out too bad. Then I just rub it into their chin real well, do it a couple times a day until the acne clears up. Amazon link: https://a.co/d/0heY2PYV

It's a blackhead. Get some hydrogel spray and put it on a couple times per day. I just spray it in my hand and rub it in well. https://a.co/d/0a64S7oG