Error after deactivating plugin

Fatal error: Uncaught Error: Class ‘WP_Super_Duper’ not found in /home/(private)/domains/(my website)/public_html/wp-content/themes/(the theme)/functions.php:17 Stack trace: #0 /home/(private)/domains/(my website)/public_html/wp-settings.php(546): include() #1 /home/(private)/domains/(my website)/public_html/wp-config.php(96): require_once(‘/home/(private)/…’) #2 /home/(private)/domains/(my website)/public_html/wp-load.php(50): require_once(‘/home/(private)/…’) #3 /home/(private)/domains/(my website)/public_html/wp-admin/admin.php(34): require_once(‘/home/(private)/…’) #4 {main} thrown in /home/(private)/domains/(my website)/public_html/wp-content/themes/(the theme)/functions.php on line 17

I can no longer access dashboard