To update your dlvr.it's API:
1) Log into your dlvr.it account
2) Go to Settings > Account
3) Under API Access, click 'reset key'
-- Your key will look something like this: 7ff2c73de716474f8f97dd1d20cc9b7b
-- If your only option is 'create key' then there is not currently an API key associated with your dlvr.it account.
4) Update the dlvr.it API key in your application