Fl in disguise

Irregular empress
prince of myolyeong
From today on I'm a boy

https://www.mangago.zone/read-manga/the_villain_discovered_my_identity/
https://www.mangago.zone/read-manga/queen_cecia_s_shorts/
https://www.mangago.zone/read-manga/my_fair_footman/ (haven't read this one)
https://www.mangago.zone/read-manga/lady_crystal_is_a_man/ (DOUBLE genderbend)
https://www.mangago.zone/read-manga/the_prince_of_myeolyeong/ (Also haven't read, but heard really good things abt it)

There was also one where the cover depicted a man (the FL cross-dressing, obviously) in a light blue suit and long brown hair. I cannot find it or remember the name for the life of me, but I read the first few chapters and it seemed good. Pointing it out so you can keep a lookout for it.

"Osora" on webtoon

I rec checking genderbend, Shoujo/romance/josei on the search page, you'll easily see all serie with disguised female lead . For example:
https://www.mangago.zone/genre/Romance,Gender%20Bender/?f=1&o=1&sortby=comment_count&e=

Or check this list of FL disguised ad a man
https://www.mangago.zone/home/mangalist/669837/

Personally I rec:
https://www.mangago.zone/read-manga/umi_no_kishidan/
https://www.mangago.zone/read-manga/chouka_kou/
https://www.mangago.zone/read-manga/love_sick/
https://www.mangago.zone/read-manga/savage_garden/
https://www.mangago.zone/read-manga/from_today_on_i_m_a_boy/
https://www.mangago.zone/read-manga/shinobi_yoru_koi_wa_kusemono/

Thank you guys sm TT