How do I modify the customized footer textual content and get theme model quantity to indicate in wordpress admin?

I’m attempting to switch the footer textual content contained in the wordpress admin and in addition get my customized themes model quantity to indicate as properly however my perform will not be working correctly, I’m nonetheless very inexperienced at PHP

~ Thank-you upfront!

perform modify_admin_footer() {
echo '<span id="footer-thankyou">Developed by <a href="http://www.toolcart.com" goal="_blank" rel="noopener noreferrer">Toolcart Theme Model:</a>.</span>';
wp_get_theme()->guardian()->Model;
}
add_filter( 'admin_footer_text', 'modify_admin_footer' );