[Gravity Form] Repeater field

functions.php

<?php

// change "3" to your form ID
add_filter( 'gform_form_post_get_meta_3', 'add_my_field' );
function add_my_field( $form ) {

    $name = GF_Fields::create( array(
        'type'   => 'text',
        'id'     => 1005,
        'formId' => $form['id'],
        'label'  => '姓名',
    ) );

    $email = GF_Fields::create( array(
        'type'   => 'email',
        'id'     => 1002,
        'formId' => $form['id'],
        'label'  => '電子郵件',
    ) );

    $phone = GF_Fields::create( array(
        'type'   => 'phone',
        'id'     => 1003,
        'formId' => $form['id'],
        'label'  => '電話',
    ) );

    $line = GF_Fields::create( array(
        'type'   => 'text',
        'id'     => 1004,
        'formId' => $form['id'],
        'label'  => 'Line ID',
    ) );

    $team = GF_Fields::create( array(
        'type'             => 'repeater',
        'description'      => '',
        'id'               => 1000,
        'formId'           => $form['id'],
        'label'            => '同行朋友資訊',
        'addButtonText'    => '新增同行朋友', // Optional
        'removeButtonText' => '刪除同行朋友', // Optional
        'maxItems'         => 5, // Optional
        'fields'           => array( $name, $email, $phone, $line ), // Add the fields here.
    ) );

    $form['fields'][] = $team;

    return $form;
}

add_filter( 'gform_form_update_meta_3', 'remove_my_field', 10, 3 );
function remove_my_field( $form_meta, $form_id, $meta_name ) {

    if ( $meta_name == 'display_meta' ) {
        $form_meta['fields'] = wp_list_filter( $form_meta['fields'], array( 'id' => 1000 ), 'NOT' );
    }

    return $form_meta;
}