https://www.mangago.me/read-manga/omega_complex_1/
https://www.mangago.me/read-manga/romance_but_not_romantic/
https://www.mangago.me/read-manga/heat_and_run/
https://www.mangago.me/read-manga/kiss_me_liar/
https://www.mangago.me/read-manga/i_like_your_pheromones/
Anyways some are Beta that became Omega and some are Recessive Omegas thinking they were Betas...
https://www.mangago.me/home/mangalist/2728457/
Omegaverse Webtoon List.. too lazy to dig sorry haha
ooking for Omegaverse that a alpha is in love with a beta and he slowly turns beta into a omega using his pheromones and it finally happens during a new years trip as they do the deed he suddenly goes into heat
also will like Omegaverse recommendations that have beta turning into omaga