create attribute. 🔐

create attribute<br/> <br/> <strong>Example Post Data:</strong><br/> <code> {<br/>     "name": "secret_id",<br/>     "type": "text",<br/>     "description": "Secret identity",<br/>     "preview_value": "real name",<br/>     "default_value": "Bruce Wayne"<br/> }<br/> </code>