While adding/editing any field you can make a certain field compulsory/required. This will make the custom field compulsory to fill.

The authors will be compelled to fill the compulsory submission fields. If they try to submit the form without filling up the compulsory fields, the submission won’t be accepted.

How to set the fields as compulsory field?

Navigate to Tevolution >> Custom fields >> Tab for the post type >> Start editing the custom field.
The fields can be set as compulsory using the validations. Turn on the validation and set the fields as compulsory fields by selecting the “required” as the validation type.

From here itself, you can also set a message to show when the required field is left empty.

Advantage

The main advantage of this feature is when you are designing a submission form for your visitors and you want certain details to be entered compulsorily. Therefore the users will not be allowed to submit the listings without entering the selected fields.