Give first and freely well before you ask and then when you do ask, make it a small request.
If you are asking too much of someone in the early stages of prospecting then you are likely missing out as many will move on.
A long form, asking to book a call or demo in the early stages of a relationship is akin to standing on the street corner with a megaphone asking for money. You might get a few dollars but most will cross the street to avoid you.
Offer value, do it at scale, be patient, ask when it is right, not when you are desperate.