Obviously take advice from a healthcare professional, as others have said. I don’t know the current advice. It constantly changes.
All three of my DC were weaned vegetarian (rather than vegan) 20 years ago and never ate meat until teenage years (when eldest two tried it themselves). They’re all v healthy and 6 foot tall! They were all breastfed for first few years.
You start off vegan anyway (rice, vegetables and fruit). When I started to introduce other things, although I gave egg, cheese, yogurt etc, most of what they ate was vegan, e.g. mild dals, risottos etc. And still is!
I used ‘Baby & Child Vegetarian Recipes’ by Carol Timperley, which I thoroughly recommend if still available. It gave me some great recipes. I’d cook them in batches and freeze in baby food-sized pots, so I always had home cooked baby food for nursery, for busy days and for taking out.
By about 12-18 months, they ate the same food as us.