You can go to the other Ask Question section and post the screenshot you have, maybe someone will recognize him?
Sorry if you already tried this!
do you mean in the "sharing" thing? sadly I don't know how to post there
There is probably an easier method but, if you click on one someone has already done, scroll all the way down till you see All Questions and click on that. Then scroll all the way down until you see Ask Question, and you should be able to !
Dion from How to Protect the Heroine’s Older Brother?
He has black hair and dark purple eyes in my screenshot but I can't find him ITS SO COMMON he's wearing a tight turtle neck and its a historical manhwa