Look at the Pushpay/CCB URL for your account.
The structure of the URL is [word].ccbchurch.com...
It is that word before the . which you need to copy or make a note of.
Example: In the image above, the word to copy or make a note of would be "Name".
Paste or type that word into the space which says 'yourwebsite'.
Continuing with our example, note how I entered "Name" in the required space.
