In order to interact with decentralized applications (DApps), you will need to pay the gas fees that push your interactions to the blockchain. The gas fees are paid in Ethereum (ETH) and cost no more than a couple of cents. There are several ways you can acquire ETH:
I. Within MetaMask with a bank account or credit/debit card
II. Within Coinbase with a bank account or credit/debit card
III. On an exchange with other cryptocurrencies
I. Within MetaMask
MetaMask is an Ethereum wallet extension that can downloaded for use on Google Chrome, Firefox, or Brave browsers. After following these steps to set-up your MetaMask, you simply have to click on the "BUY" or "DEPOSIT" button (depending on which version of MetaMask you're using). Click on Coinbase as the market and follow the instructions to purchase your ETH.
II. Within Coinbase
Once you do so, you will have to transfer your ETH from Coinbase to your MetaMask wallet in order to utilize the ETH to interact with the adChain Registry. You can follow these instructions to transfer your ETH from Coinbase to your MetaMask. The destination address is your MetaMask public address.
III. On an Exchange
Pretty much every cryptocurrency exchange offers the purchase of ETH through other cryptocurrencies. Simply follow the exchange's instructions in converting your crypto to ETH and export the ETH to your MetaMask wallet. The destination address is your MetaMask public address.