Is it sad to ask someone to send me a voice note when they get online or when they feel alone and they ignore me?

It depends on the relationship, but assuming the right relationship, it seems like a simple request.

And we all have our own needs or desires, which can sometimes be different than others.

Like sometimes I need to know that someone cares, or hear from someone, anyone I know, basically signaling that I'm included in some sort of circle, and not left out of the world and all alone.