Add integration?

Fatal error: Uncaught TypeError: Cannot access offset of type string on string in /var/www/popup4phone/html/wp-content/plugins/popup4phone/includes/components/form.php:143 Stack trace: #0 /var/www/popup4phone/html/wp-includes/shortcodes.php(356): Popup4Phone_Form->shortcode_inline_form_no_popup('', '', 'popup4phone_inl...') #1 [internal function]: do_shortcode_tag(Array) #2 /var/www/popup4phone/html/wp-includes/shortcodes.php(228): preg_replace_callback('/\\[(\\[?)(popup4...', 'do_shortcode_ta...', '[popup4phone_in...') #3 /var/www/popup4phone/html/wp-content/plugins/ivan-landing-page/lp-integration.php(23): do_shortcode('[popup4phone_in...') #4 /var/www/popup4phone/html/wp-content/plugins/ivan-landing-page/ivan-landing-page.php(114): include('/var/www/popup4...') #5 /var/www/popup4phone/html/wp-includes/class-wp-hook.php(303): PageTemplater->the_content('') #6 /var/www/popup4phone/html/wp-includes/plugin.php(189): WP_Hook->apply_filters('', Array) #7 /var/www/popup4phone/html/wp-includes/post-template.php(253): apply_filters('the_content', '') #8 /var/www/popup4phone/html/wp-content/themes/unite-child/content-page.php(15): the_content() #9 /var/www/popup4phone/html/wp-includes/template.php(772): require('/var/www/popup4...') #10 /var/www/popup4phone/html/wp-includes/template.php(716): load_template('/var/www/popup4...', false, Array) #11 /var/www/popup4phone/html/wp-includes/general-template.php(204): locate_template(Array, true, false, Array) #12 /var/www/popup4phone/html/wp-content/themes/unite-child/page.php(20): get_template_part('content', 'page') #13 /var/www/popup4phone/html/wp-includes/template-loader.php(106): include('/var/www/popup4...') #14 /var/www/popup4phone/html/wp-blog-header.php(19): require_once('/var/www/popup4...') #15 /var/www/popup4phone/html/index.php(17): require('/var/www/popup4...') #16 {main} thrown in /var/www/popup4phone/html/wp-content/plugins/popup4phone/includes/components/form.php on line 143