What’s a polite way to tell someone they have body odour?

Well you must be so kind to tell someone they don’t smell all that pleasant in the first place. Providing solution will be one of the most polite way ever .
first you’ll get them deodorant and body spray and perfume, then you tell them to always apply it that it would help them in cause they don’t smell all that nice. You’ll also go ahead and tell them to always use soap when bathing, or to change the ones they use cause it might be contributing to their present predicament