You may have up to three options.
BBM - If you are comfortable really breaking down your bike when disassembling and packing it. You will have to remove both wheels plus many other components like bars/stem, pedals, rear derailleur, rotors and seat and seatpost. An advantage to using this box is that it gives you the best rates because it’s the smallest of your three box options. It ships great (economically) internationally, too.
BBL - With this easy-to-pack option, your rear wheel stays on. Yes, you still have to remove some other components but not as many as for the BBM. It ships well domestically and internationally.
BBXL - With this easy-to-pack option, you remove both wheels, but you can leave most road/gravel bike bars on. Often, you can even leave your aerobars on!. This is a great option if you want to keep your bars and stem in place while shipping. It’s also great if you have an integrated (one-piece) bar and stem or if you want to stash a spare set of wheels in your box. This box ships best domestically, and it may not fare for some international shipments.