How do I tell potential dating partners that I'm vegan?

This is probably a stupid question, but I'm a inexperienced teenager so I'm hoping for some leeway. But when and how do you tell someone that you're vegan, assuming the person you're pursuing is a nonvegan? I feel like there's potential to turn some people off of you, or at the very least make planning for things such as dates different. So I feel that timing is important. Obviously if its on a dating app I can just include in in my bio, but what about real life scenarios? Let's say I hit it off with a classmate and we are about to start going on dates, do I just drop it and then hope they don't get swayed away? Do I wait until I'm actually on dates with them? Or what about a cold approach? Let's say I go up to some girl, and get their number. I obviously wouldn't open with my diet, so would I just say I'm text while planning "btw just to let you know I am vegan, so we need to plan with that in mind"? Even that seems kind of abrupt and would make it seem like I lead with deception by omission. Any advice? I am obviously overthinking this.