The answer to this question depends on the total size of the tank. While some small UTV sprayers can be lifted by two-three people, anything larger will require mechanical help in the shape of a forklift on your tractor or loader.
That being said, UTV sprayers come in handy when looking to fertilize or spray weed killers on relatively small surfaces, where using a regular backpack sprayer might take too much time. In all other situations, it is best to know how to handle the heavy equipment and how to look after it or refill it once needed.
Keep in mind that using a loader also requires training and knowledge, so you might need professional help whenever handling heavy machines and platforms. If you cannot rely on your farming and mechanical skills, it is always best to ask others for help, including when you need to lift your UTV sprayer with the help of a loader.