Fatal Plugin Error

I’m getting the following error:

Fatal error: Uncaught Error: Using $this when not in object context in /home/991195.cloudwaysapps.com/bwfkhrpwmt/public_html/wp-content/plugins/radio-station-pro/includes/rsp-player.php:419 Stack trace: #0 /home/991195.cloudwaysapps.com/bwfkhrpwmt/public_html/wp-includes/class-wp-hook.php(308): radio_station_pro_player_widget_fields() #1 /home/991195.cloudwaysapps.com/bwfkhrpwmt/public_html/wp-includes/plugin.php(205): WP_Hook->apply_filters() #2 /home/991195.cloudwaysapps.com/bwfkhrpwmt/public_html/wp-content/plugins/radio-station/widgets/class-radio-player-widget.php(247): apply_filters() #3 /home/991195.cloudwaysapps.com/bwfkhrpwmt/public_html/wp-includes/class-wp-widget.php(535): Radio_Player_Widget->form() #4 /home/991195.cloudwaysapps.com/bwfkhrpwmt/public_html/wp-admin/includes/widgets.php(274): WP_Widget->form_callback() #5 /home/991195.cloudwaysapps.com/bwfkhrpwmt/public_html/wp-includes/class-wp-customize-widgets.php(1148): wp_widget_control() #6 /home/991195.cloudwaysapps.com/bwfkhrpwmt/public_html/wp-includes/ in?/home/991195.cloudwaysapps.com/bwfkhrpwmt/public_html/wp-content/plugins/radio-station-pro/includes/rsp-player.php?on line?419