Why can't I buy helium?

Could you elaborate on why I'm encountering difficulties in purchasing helium? Is there a specific reason why the market seems inaccessible to me? Are there any regulatory restrictions or technical barriers that I'm unaware of? Perhaps the cryptocurrency exchange I'm using doesn't support helium transactions. Alternatively, could it be a supply issue, with helium being in high demand and low supply? Clarifying these points would greatly assist me in navigating the cryptocurrency market and understanding why I'm unable to acquire helium at this time.