I’m not familiar with it too.. but you can recognise it’s BL if it’s written on the cover. I mostly search online for BL webtoons through other sites. There was a topic where someone asked for webtoon recs not too long ago but I can’t find it. TT If you want a rec though, CRUSHED!! is pretty interesting.
my absolute favorite: https://www.webtoons.com/en/super-hero/the-fever-king/list?title_no=1659
https://www.webtoons.com/en/challenge/jamie/list?title_no=195567
https://www.webtoons.com/en/challenge/heartstopper/list?title_no=329660
https://www.webtoons.com/en/challenge/novae/list?title_no=106507
https://www.webtoons.com/en/challenge/camellia/list?title_no=81223
https://www.webtoons.com/en/challenge/vermelho-bl/list?title_no=171841
https://www.webtoons.com/en/challenge/the-reaper-and-the-waiting/list?title_no=311439
not really a BL (there's a budding romance between two of the boys in the recent chapters though) but it's still an amazing story: https://www.webtoons.com/en/challenge/green-gold/list?title_no=93055
Here is my webtoon list.
♡Yaoi♡ with explicite scenes:
http://www.mangago.zone/home/mangalist/765207/
And ☆Shounen Ai☆. No scenes includes sex.
http://www.mangago.zone/home/mangalist/765200/
Does Webtoons contain BL? I don't find the BL tag in Genres. And I couldn't find any BL as of now.