Fatal error: Cannot redeclare tgmpa() (previously declared in

Hello, i installed the plugin WordPress Form Customizer | CF7 Customizer And then gave me this error

Fatal error: Cannot redeclare tgmpa() (previously declared in/homepages/26/d623997876/htdocs/clickandbuilds/MiHistoriadeViaje/wp-content/plugins/cf7-customizer/assets/admin/inc/tgm/class-tgm-plugin-activation.php:2126) in /homepages/26/d623997876/htdocs/clickandbuilds/MiHistoriadeViaje/wp-content/themes/travelwp/inc/admin/required-plugins/class-tgm-plugin-activation.php on line 2118

Please help me.