Access array offset on value of null Issue Fixing

feature_icon_type.php

<?php
        $feature_image = '';
        if (($settings['feature_icon_type'] ?? '') == 'img') {
            $feature_image = Group_Control_Image_Size::get_attachment_image_html($settings, 'feature_imagesize', 'feature_image');
        }

        $html_output = '';
        $html_output .= '<div ' . $this->get_render_attribute_string('growth_feature_attr') . ' >';
        if (!empty($feature_image)) {
            $html_output .= '<div class="feature-icon">' . $feature_image . '</div>';
        } elseif ($settings['feature_icon_type'] == 'icon' and !empty($settings['feature_icon'])) {
            $html_output .= '<div class="feature-icon"><i class="' . esc_attr($settings['feature_icon']) . '"></i></div>';
        }