Install the plugin User Access Shortcodes to give you access to the [UAS_loggedin] shortcode.
Then simply put the form shortcode between the opening and closing shortcodes.
1 2 3 | [UAS_loggedin] [quform id="1" name="Contact form"] [/UAS_loggedin] |
[UAS_loggedin] [quform id="1" name="Contact form"] [/UAS_loggedin]
If you want to show a message to logged out users you can use the [UAS_guest] shortcode.
1 2 3 | [UAS_guest] Please <a href="/wp-login.php">log in</a> to submit this form. [/UAS_guest] |
[UAS_guest] Please <a href="/wp-login.php">log in</a> to submit this form. [/UAS_guest]