Gravity froms plugin and addon conflict

Whenever, i add the Gravity Forms Send to Third-Party API addon, whenever i send the form this error keeps popping up:

Uncaught Error: Call to a member function get_input_type() on null in /home/tefsip80gigs/public_html/wp-content/plugins/gravityplus-third-party-post/includes/class-addon.php:953 Stack trace: #0 /home/tefsip80gigs/public_html/wp-content/plugins/gravityplus-third-party-post/includes/class-addon.php(698): GFP_Third_Party_Post_Addon->get_request_body(Array, Array, Array) #1 /home/tefsip80gigs/public_html/wp-content/plugins/gravityplus-third-party-post/includes/class-addon.php(676): GFP_Third_Party_Post_Addon->post_data_to_external_api(Array, Array, Array) #2 /home/tefsip80gigs/public_html/wp-content/plugins/gravityforms/includes/addon/class-gf-feed-addon.php(338): GFP_Third_Party_Post_Addon->process_feed(Array, Array, Array) #3 /home/tefsip80gigs/public_html/wp-includes/class-wp-hook.php(290): GFFeedAddOn->maybe_process_feed(Array, Array) #4 /home/tefsip80gigs/public_html/wp-includes/plugin.php(206): WP_Hook->apply_filters(Array, Array) #5 /home/tefsip80gigs/public_html/wp-content/plugins/gravityforms/gravityform in /home/tefsip80gigs/public_html/wp-content/plugins/gravityplus-third-party-post/includes/class-addon.php on line 953

How do I resolve it? My website is http://tefsip.80gigs.com

I recommend checking with support for that plugin: