I recommend sunscreen!

I'm a guy so I rarely wear sunscreen, but now that I'm in my late 30s, my skin has gotten incredibly dull. I already have dark skin, so the dark circles under my eyes are really bad. So I recently started wearing sunscreen. I didn't want to just buy something cheap from Daiso or something. I'm using Hera For Men sunscreen from Costco. I was recommending sunscreen, but it's a bit pricey. If that's too much of a burden, you can just buy a bulk pack from Daiso and slather it all over your face.

As for sunscreen recommendations,

Herager is fine, and it's also good to buy it at a good price from Coupang.

In fact, I think it's more important to apply sunscreen diligently every day than to use sunscreen.