Add custom field to Registration form

Hello

I am trying to add a custom field to registration form.
I have done following changes in page-signup.php file

// CUSTOM FIELD VIEW
// Added a custom field $cf_org

function show_user_form( $user_name = '', $user_email = '', $cf_org = '', $errors = '' ) {
	if ( ! is_wp_error( $errors ) ) {
		$errors = new WP_Error();
	}

	// User name
	echo '<label for="user_name">' . __( 'Username:' ) . '</label>';
	$errmsg = $errors->get_error_message( 'user_name' );
	if ( $errmsg ) {
		echo '<p class="error">' . $errmsg . '</p>';
	}
	echo '<input name="user_name" type="text" id="user_name" value="' . esc_attr( $user_name ) . '" autocapitalize="none" autocorrect="off" maxlength="60" /><br />';
	_e( '(Must be at least 4 characters using lowercase letters and numbers only.)' );
	?>

	<label for="user_email"><?php _e( 'Email&nbsp;Address:' ); ?></label>
	<?php
	$errmsg = $errors->get_error_message( 'user_email' );
	if ( $errmsg ) {
		?>
		<p class="error"><?php echo $errmsg; ?></p>
	<?php } ?>
	<input name="user_email" type="email" id="user_email" value="<?php echo esc_attr( $user_email ); ?>" maxlength="200" /><br /><?php _e( 'We send your registration email to this address. (Double-check your email address before continuing.)' ); ?>
	<?php
	$errmsg = $errors->get_error_message( 'generic' );
	if ( $errmsg ) {
		echo '<p class="error">' . $errmsg . '</p>';
	}

	// CU FIELD
	$team_posts = get_posts([
		'post_type' => 'wc_memberships_team',
		'post_status' => 'publish',
		'numberposts' => -1,
		'orderby'=> 'title',
		'order' => 'ASC'
	]);
	$teams = [];
	$team_posts = check_duplicate_teams($team_posts); 
	?>

	<label for="cf_org "><?php _e( 'Organization:' ); ?></label>
	<?php
	$errmsg = $errors->get_error_message( 'cf_org ' );
	if ( $errmsg ) {
		?>
		<p class="error"><?php echo $errmsg; ?></p>
	<?php } ?>
	<select name="cf_org " id="cf_org ">
		<option value=""> -- Select your Organization -- </option>
		<?php 
   // An array coming from PHP with values 
   foreach( $team_posts as $team){ ?>
			<option value="<?php echo $team ?>"> <?php echo $team ?> </option>
		<?php } ?>
	</select>
	<?php
	$errmsg = $errors->get_error_message( 'generic' );
	if ( $errmsg ) {
		echo '<p class="error">' . $errmsg . '</p>';
	}

	
	/**
	 * Fires at the end of the user registration form on the site sign-up form.
	 *
	 * @since 3.0.0
	 *
	 * @param WP_Error $errors A WP_Error object containing 'user_name' or 'user_email' errors.
	 */
	do_action( 'signup_extra_fields', $errors );
}

After adding above code, i am able to see a custom field in User Registraion form. But data is not saving into database.

I have further elaborated the code and found that data is being saved using wpmu_signup_user() So i have added custom field value but still it is not saving. see below code.

 function validate_user_signup() {
	$result     = validate_user_form();
	$user_name  = $result['user_name'];
	$user_email = $result['user_email'];
	$cf_org = $_POST['cf_org '];
	$errors     = $result['errors'];

	if ( $errors->has_errors() ) {
		signup_user( $user_name, $user_email, $cf_org , $errors );
		return false;
	}

	if ( 'blog' == $_POST['signup_for'] ) {
		signup_blog( $user_name, $user_email );
		return false;
	}

//echo 'cu';
//print_r($cf_org );
	//die('');
	/** This filter is documented in wp-signup.php */
	wpmu_signup_user( $user_name, $user_email, apply_filters( 'add_signup_meta', array('cf_org ' => $cf_org ) ) );

	confirm_user_signup( $user_name, $user_email );
	return true;
}

Please confirm, what steps do i need to do to save this value in Database or where i am doing wrong.

Thank you