I know omega-verse plays it fast and loose with the rules so it can be hard to know what type they're going for at first. In this case whatever is going on down there it's either magically gone or waaaay different than standard since she is hiding as a "beta" fashion model who does photoshoots including swimwear. The majority of time it seems like she can physically pass without any concerns.
Generally, when it comes to AFAB Alphas, they will generally have a retractable phallus. It's either a clitoris that becomes erect, or is in the urethra area. Tho there are some who do AFAB Alphas as futa or trans women without bottom surgery. There are very few hard and fast rules in ABO/Omegaverse work, outside of the Roles, heat/rut, scenting etc.
Source: currently working on an ABO/Omegaverse webtoon and did way too much research.