Gravity Forms - Dynamic Dropdown, Radio Button, Multi Select

functions.php

<?php
/*-----------------------------------------------------------------------------------*/
/* Putting Locations in a Dropdown, Radio Button, or Multi-Select */
/* Helpful article - https://www.gravityhelp.com/documentation/article/dynamically-populating-drop-down-fields/  */
/*-----------------------------------------------------------------------------------*/
$location_form_id = 9;
add_filter( 'gform_pre_render_'.$location_form_id, 'populate_posts' );
add_filter( 'gform_pre_validation_'.$location_form_id, 'populate_posts' );
add_filter( 'gform_pre_submission_'.$location_form_id, 'populate_posts' );
add_filter( 'gform_pre_submission_filter_'.$location_form_id, 'populate_posts' );
add_filter( 'gform_admin_pre_render_'.$location_form_id, 'populate_posts' );
function populate_posts( $form ) {
    foreach ( $form['fields'] as &$field ) {
        if ( $field->label == 'Location') {
		$posts = get_posts( 'post_type=location&orderby=title&order=ASC' );
			  /* Other qualifiers on https://codex.wordpress.org/Template_Tags/get_posts */
		$choices = array(); 
		foreach ( $posts as $post ) {
		    $choices[] = array( 'text' => $post->post_title, 'value' => $post->post_title );
		}
		// I added this line to add 'Other Post' in case you want a different value not listed.  
		//   Then you can use conditional logic to show a field in the case this option is selected
		$choices[] = array('text' => 'Other Post', 'value' => 'Other Post');
		
		// update 'Select a Post' to whatever you'd like the instructive option to be
		$field->placeholder = 'Select a Post';
		$field->choices = $choices;
        }
    }
 return $form;
}
?>