What is nebulasexual?

I'm curious, can you explain what nebulasexual means? I've come across this term recently and I'm intrigued to learn more about its origins and how it's used in the context of sexual identity and expression. Is it a relatively new concept or has it been around for a while? How do individuals who identify as nebulasexual view their own sexuality, and how do they navigate their relationships and romantic attractions in light of this identity?