Blockstream Green is not a platform for buying and selling bitcoin. Blockstream Green is a Bitcoin wallet, which is a way for you to securely receive, store, and send bitcoin and Liquid Assets. If you wish to buy or sell bitcoin, or exchange it for other currencies, you will need to use another method, such as a cryptocurrency exchange, a bitcoin ATM, etc. We are unable to provide guidance for finding a service to buy/sell bitcoin, as this can depend greatly on your own personal needs and location. After you have bought some bitcoin, you can send it to your Blockstream Green wallet by using the wallet’s Receive function. If you wish to sell your Bitcoin, you will have to use the Send function to send it to a service that will let you sell it.