functions.php

<?php

/**
 * ConvertKit Settings Content
 *
 */
function be_wpforms_settings_section_content( $instance ) {
    echo '<div class="wpforms-panel-content-section wpforms-panel-content-section-be_convertkit">';
    echo '<div class="wpforms-panel-content-section-title">' . __( 'ConvertKit', 'be_wpforms_convertkit' ) . '</div>';

    wpforms_panel_field(
        'text',
        'settings',
        'be_convertkit_api',
        $instance->form_data,
        __( 'ConvertKit API Key', 'be_wpforms_convertkit' )
    );

    wpforms_panel_field(
        'text',
        'settings',
        'be_convertkit_form_id',
        $instance->form_data,
        __( 'ConvertKit Form ID', 'be_wpforms_convertkit' )
    );

    wpforms_panel_field(
        'select',
        'settings',
        'be_convertkit_field_first_name',
        $instance->form_data,
        __( 'First Name', 'be_wpforms_convertkit' ),
        array(
            'field_map'   => array( 'text', 'name' ),
            'placeholder' => __( '-- Select Field --', 'be_wpforms_convertkit' ),
        )
    );

    wpforms_panel_field(
        'select',
        'settings',
        'be_convertkit_field_email',
        $instance->form_data,
        __( 'Email Address', 'be_wpforms_convertkit' ),
        array(
            'field_map'   => array( 'email' ),
            'placeholder' => __( '-- Select Field --', 'be_wpforms_convertkit' ),
        )
    );

    echo '</div>';
}
add_filter( 'wpforms_form_settings_panel_content', 'be_wpforms_settings_section_content', 20 );