function input_admin_enqueue_scripts() {
$cm_settings['codeEditor'] = wp_enqueue_code_editor(
array('type' => 'text/html')
);
wp_localize_script('jquery', 'cm_settings', $cm_settings);
wp_enqueue_script('wp-theme-plugin-editor');
wp_enqueue_style('wp-codemirror');
}
<script>
jQuery(document).ready(function($) {
var evhcaCodeEditors = document.querySelectorAll( '.custom-selector-for-your-textarea-field' );
for ( var i = 0; i < evhcaCodeEditors.length; i++ ){
wp.codeEditor.initialize( $(evhcaCodeEditors[i]), cm_settings );
}
});
</script>
