Where can I buy Blender Network Coins?

Excuse me, could you please elaborate on the availability of Blender Network Coins? I'm quite interested in acquiring some, but I'm unsure of the most suitable platform or exchange to do so. Could you recommend a reliable source where I can safely purchase Blender Network Coins? Also, do you happen to know if there are any specific requirements or restrictions I should be aware of before making such a transaction? Thank you in advance for your assistance.