I got this fatal error after installing theme… I am hosting it on goddady wordpress managed and other themes work fine..

Fatal error: Uncaught TypeError: join(): Argument #2 ($array) must be of type ?array, string given in /var/www/wp-content/themes/flatbase/engine/admin/classes/class-nice-web-font-subscriber.php:111 Stack trace: #0 /var/www/wp-content/themes/flatbase/engine/admin/classes/class-nice-web-font-subscriber.php(111): join(Array, ‘|’) #1 /var/www/wp-content/themes/flatbase/engine/admin/typography.php(163): Nice_Web_Font_Subscriber->get_uri(Array) #2 /var/www/wp-content/themes/flatbase/includes/theming/typography.php(154): nice_get_web_fonts_uri() #3 /var/www/wp-includes/class-wp-hook.php(307): nice_theme_web_fonts(”) #4 /var/www/wp-includes/class-wp-hook.php(331): WP_Hook->apply_filters(NULL, Array) #5 /var/www/wp-includes/plugin.php(476): WP_Hook->do_action(Array) #6 /var/www/wp-includes/script-loader.php(2156): do_action(‘wp_enqueue_scri…’) #7 /var/www/wp-includes/class-wp-hook.php(307): wp_enqueue_scripts(”) #8 /var/www/wp-includes/class-wp-hook.php(331): WP_Hook->apply_filters(NULL, Array) #9 /var/www/wp-includes/plugin.php(476): WP_Hook->do_action(Array) #10 /var/www/wp-includes/general-template.php(3042): do_action(‘wp_head’) #11 /var/www/wp-content/themes/flatbase/header.php(40): wp_head() #12 /var/www/wp-includes/template.php(770): require_once(‘/var/www/wp-con…’) #13 /var/www/wp-includes/template.php(716): load_template(‘/var/www/wp-con…’, true, Array) #14 /var/www/wp-includes/general-template.php(48): locate_template(Array, true, true, Array) #15 /var/www/wp-content/themes/flatbase/template-home.php(20): get_header() #16 /var/www/wp-includes/template-loader.php(106): include(‘/var/www/wp-con…’) #17 /var/www/wp-blog-header.php(19): require_once(‘/var/www/wp-inc…’) #18 /var/www/index.php(17): require(‘/var/www/wp-blo…’) #19 {main} thrown in /var/www/wp-content/themes/flatbase/engine/admin/classes/class-nice-web-font-subscriber.php on line 111