You should only ask for your guest's flight number when it is relevant. If you decide to automate that part, or you have information that is specific for guests who are likely to fly to your location, then you can create a custom code with a specific condition for this.
Here is how:
Go to Hospitable > Guest experience
Custom codes
Create a new custom code or use an existing one
Name it the way you like (such as
%%ask_for_flight%%).Include the relevant text
Set the condition to '
The guest will take a plane'
Don't forget to include your custom code in your messaging rule, where you want the text to be communicated.
When your guest is likely to take a flight (because driving would be very long or there is no other way to travel), this condition will be triggered. If not, the condition will not be triggered and the text will not be included in your message.