I'll second Hitchcocks especially for their online parts manual, though they don't stall everything, they were the first to get the parts reference available and online for the Euro5 based models and once you know the part number and what Royal Enfield actually call the part the job is much easier. I'm thinking of trafficators specifically as I write this. Seconding https://www.bike-parts-royalenfield.com as it also has a great site especially if you know your part number, though I haven't actually needed to purchase a part I didn't find elsewhere.Where can I buy replacement parts for a 2020 Himalayan? I look on Hitchcock's, and look at the diagrams for specific parts, but they all say out of stock.
NOT SAYING that there is anything bad about that site, indeed its a very useful resource.