I suggest using a combination of visual and verbal cues to help your toddler develop this skill. One strategy is to use simple, clear language when asking for specific body parts, such as "Where's your elbow?" instead of more general phrases like "Where's your tummy?"
You could also try using mirror work to reinforce the connection between the words and their correct body part locations. For example, while looking in a mirror, point to each other's body part and say its name. This can help your child develop an association between the verbal cues and the physical parts.
Another approach is to gradually increase the difficulty of the pointing requests by using more complex sentences or asking for less common body parts. You could also try using pointing cards with pictures or first-letter clues to help your child develop their problem-solving skills and make connections between words and body parts.
Lastly, be sure to provide consistent and clear feedback when your child responds incorrectly, as this will help them develop a sense of which answers are acceptable. For instance, if they point to their knee instead of their elbow, you could gently say "That's close! The correct answer is my elbow." This approach might encourage them to keep practicing until they get it right.