That is indeed an interesting question. I would like to help you, indeed! You would, indeed, like to know the answer to that question. You use it to add emphasis. Here are some other examples: https://sentence.yourdictionary.com/indeed

Is is often used similarly to "certainly". "He certainly is a tall person" or "he indeed is a tall person." The difference is that, as someone mentioned, "indeed" is usually used to confirm what someone said previously. If my friend said to me, "my cousin is very tall," when I later saw the cousin, I would say "he is indeed very tall." If we were walking on the street and I saw a stranger, I would say, "he is certainly very tall," and my friend might look and say, "yes, he is indeed very tall." (He could say "certainly" here as well, but I would not say "indeed" in the first sentence; that would sound odd)

Indeed is used to emphasise a true statement or a response to confirm something already stated e.g. "The man was attractive and indeed so was the woman" e.g. Person 1: "It appears the cookie has be stolen" Person 2: "Indeed"

"Indeed" is like "¡Cierto!" or "¡Es verdad!"