Employee First Name First Letter in Capital

Summary:

We need validation for Employee First Name(Deliver field), In case if users enter employee First name in a Small letter it should display the Error message, i.e, First Name = mark *** Error message, should be 'Please enter the Employee First name first Letter in Capital letter Example "Mark" instead of "mark" '

We don't know how to enable this validation through Autocomplete Rule. Please can you guide me?

Content (required):

Version (include the version you are using, if applicable):

21C (11.13.21.07.0)

Code Snippet (add any code snippets that support your topic, if applicable):