an error after I added my widget

Hi there, I was installed the plugin, and I get this error:

Fatal error: Uncaught ValueError: Unknown format specifier ";" in /home/hamad/web/hmdqr.me/public_html/wp-content/plugins/ko-fi-button/Ko_fi.php:241 Stack trace: #0 /home/hamad/web/hmdqr.me/public_html/wp-content/plugins/ko-fi-button/Ko_fi.php(241): sprintf('<iframe id="kof...', 'hmdqr') #1 /home/hamad/web/hmdqr.me/public_html/wp-content/plugins/ko-fi-button/class-ko-fi-panel-widget.php(49): Ko_Fi::get_panel_embed_code(Array, 'ko_fi_panel_wid...') #2 /home/hamad/web/hmdqr.me/public_html/wp-includes/class-wp-widget.php(393): Ko_Fi_Panel_Widget->widget(Array, Array) #3 /home/hamad/web/hmdqr.me/public_html/wp-includes/widgets.php(835): WP_Widget->display_callback(Array, Array) #4 /home/hamad/web/hmdqr.me/public_html/wp-content/themes/twentytwentyone/template-parts/footer/footer-widgets.php(13): dynamic_sidebar('sidebar-1') #5 /home/hamad/web/hmdqr.me/public_html/wp-includes/template.php(772): require('/home/hamad/web...') #6 /home/hamad/web/hmdqr.me/public_html/wp-includes/template.php(716): load_template('/home/hamad/web...', false, Array) #7 /home/hamad/web/hmdqr.me/public_html/wp-includes/general-template.php(204): locate_template(Array, true, false, Array) #8 /home/hamad/web/hmdqr.me/public_html/wp-content/themes/twentytwentyone-child/footer.php(19): get_template_part('template-parts/...') #9 /home/hamad/web/hmdqr.me/public_html/wp-includes/template.php(770): require_once('/home/hamad/web...') #10 /home/hamad/web/hmdqr.me/public_html/wp-includes/template.php(716): load_template('/home/hamad/web...', true, Array) #11 /home/hamad/web/hmdqr.me/public_html/wp-includes/general-template.php(92): locate_template(Array, true, true, Array) #12 /home/hamad/web/hmdqr.me/public_html/wp-content/themes/twentytwentyone/page.php(25): get_footer() #13 /home/hamad/web/hmdqr.me/public_html/wp-includes/template-loader.php(106): include('/home/hamad/web...') #14 /home/hamad/web/hmdqr.me/public_html/wp-blog-header.php(19): require_once('/home/hamad/web...') #15 /home/hamad/web/hmdqr.me/public_html/index.php(17): require('/home/hamad/web...') #16 {main} thrown in /home/hamad/web/hmdqr.me/public_html/wp-content/plugins/ko-fi-button/Ko_fi.php on line 241
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