From your Funnel Pages Dashboard, head over to Businesses. 

From here select the Business you’ve created that will use a White Label domain, Once the business is selected head over to SETUP > WHITE LABEL

From the White Label screen, make sure to input the White Label Domain as shown here and to set the A record of your Domain to target our IP Address as shown here:

For the Whole Process take a look at this screen:

For an instructional video please take a look here:

https://drive.google.com/open?id=1h_yQHiCzs7gynWoa9bmEX0vzS75iovcf