How to change custom values
Navigate to Settings > Custom Values
Click on the ⋮ Icon > Edit Custom Value
Update the 'Value' section
Press 'Update'
After this, any automations you have which use custom values will use the the new value you just inputted instead.
Common errors changing custom values
Changing the name instead of the value
If notice that the automated messages being sent out are still empty after changing your custom value, it may be because you modified the 'Name' field and left the 'Value' field blank by accident.
All you would have to do is modify the Value field so it contacts the text you want to be sent inside of your automated messages.