I am interested in finding out if I qualify for a 144 hour free Chinese visa

And how do I get the paperwork to show that I do qualify.
We are 2 couples flying to Singapore on March 7, 2018. The four of us hold US passports. On March 11 we board the Majestic Princess Cruise ship and disembark on March 25, 2018 at the Shanghai Port, Wusongkou. We have a private Chinese guide that will show us Shanghai for less than 144 hours. We will fly out of Shanghai on March 29th 2018. We fly on Delta Airlines from Shanghai to Beijing (5 hour layover in the airport) in transit to Detroit, USA. Final destination is Tampa FL. on March 29, 2018.
I need to know soon as our trip is about 3 weeks away.
Thank you.