I wired everything up in ETH.BUILD to send a transaction but it would never get submitted. I was not seeing any error messages so I deleted everything and created it again. Still no luck.
What I did next was use the Developer Tools of my browser to see what was happening on the network. From there I could see that my sending account did not have enough fund to cover the gas to send the transaction
I used MetaMask to send more Eth to the sending account and then I could send the transaction from ETH.BUILD.