How do I make a field required?

Step-by-step guide

Select the Module link in the top left banner then select the appropriate module name link.
Select the Forms tab.
Then select the Field List button "Create/Update Fields".
Using the search filter in the upper left search for the field you wish to make required.
Select the Edit pencil icon on the field.
Select the Validation tab.
Check the Required checkbox.
Click the Update button and then click Save.
The field will now require a value on the form.