How to buy Blockbank on the app?

Could you please elaborate on the steps involved in purchasing Blockbank through the app? I'm particularly interested in understanding the process from start to finish. For instance, do I need to set up an account first? What are the necessary verification steps? Are there any fees associated with the purchase? Additionally, is there a minimum or maximum amount I can buy? And finally, how long does the entire process typically take? I'd appreciate a detailed explanation to ensure a smooth and secure transaction.