How to automatically copy account name to the contact Full Name field, if the field is empty

Case

Need help with the following scenario:

In contacts module, IF Full Name = “Empty”, then copy account name to Full Name field and save record.

Solution

As an example you can use this process model:

Make sure you connect the elements with each other by setting up the filtering by the record id. 

For example,

Please connect all the objects and then check the process.