Step 1 - Please make sure you have your script created prior to linking to the campaign.
(https://support.ytel.com/en/articles/1643998-scripts)
Click on Campaigns > Campaign
Locate the appropriate campaign and then click on Modify
Scroll to the "General Settings" area, locate the drop-down for Script and select the script you would like to be used.
We're here to help - if you need assistance, please contact the Ytel support team via email at support@ytel.com or you can click the live chat button at the bottom right of your screen.