Buying Theta, Theta Fuel using the ChangeAngel swap site
Theta and Tfuel use the same address in the Theta wallet.
1. Purchase USDC coin on Coinbase (Buy/Sell select USDC) and wait 3-4 days so it can be withdrawn. For instant withdrawals purchase with your debit card (higher fees) instead of bank ACH transfer. USDC is a stable coin like a crypto dollar that doesn't fluctuate and there is no fee to buy it on Coinbase.
2. Go to ChangeAngel.io and select USDC on the top (send) and Theta on the bottom (receive). Enter in the exact amount of USDC you'd like to purchase Theta with. (I leave out $5 - $10 from my total USDC on Coinbase for fees just in case, I do not send the full amount I have.) Click Exchange.
4. Enter in your Theta Wallet address (go to ThetaToken.org and download a wallet or simply install the app on your phone. Copy the receiving address from the wallet and paste it into ChangeAngel.
5. When asked for the refund address, go to Coinbase, click Send/Recieve button, Receive, select USDC. Copy the receiving address and paste it into ChangeAngel. (There is a button on the bottom “Copy Sending Address”.)
6. When it shows your transaction take a picture for your records. Check Agree box and Next. Sign up (not "sign in”, scroll down) if you need to create an account—it is very simple, just an email. They send you a temporary password.
7. Do the last step to complete the transaction. They will provide an address where you will be sending the USDC from Coinbase to. Copy that address and paste it into Coinbase (Send/Receive button, Send USDC). Steps: Select Send to field: USDC, then paste in the address, then select the EXACT amount you are sending and confirm the transaction.
I am sure to note down how much I'm buying, at what price the coin is, the date, anything I can for my records.
Check your Theta Wallet sometime later to see that it arrived!
p.s.
Before I started using ChangeAngel, this was how I bought Theta, which is still a great option. The video provides a good tutorial on the overall process, which can be applied to ChangeAngel too.
I buy THETA on Simpleswap.io this way: https://www.youtube.com/watch?v=vE3-5ffRiIo&t=321s
You can swap any coin for any coin--IF they allow that pairing (this can change). Try BTC or USDT or USDC or ETH, etc paired to your coin and see which one will work. BTC and ETH have high fees in their blockchain network so I prefer stable coins or LTC.
My tip is just be sure to send the exact amount that you entered in. If you type .25 ETH or whatever, send .25 ETH from the wallet or exchange, not .251. Do this within the ten minute time period from pressing the “Exchange” button. It’s easy once you get the hang of it but I am happy to help you if you need. Be sure to properly set up your wallet beforehand!
Update: if this doesn’t work for some reason (“the pair is not supported”) it’s also fine to use Changeangel.io. One client had trouble with Coinbase cancelling the transaction from ChangeNOW! So we used ChangeAngel and that worked. I also believe ChangeAngel has lower fees than SimpleSwap, which are donated to the Digibyte Foundation, yay! Same process as the SimpleSwap video above, but applied to ChangeAngel.