Am I covered by 144 hrs visa- free transit?

I'll be flying from Munich to Shanghai Pudong landing on Jan 19/19 and staying in Hotel in Shanghai for 3 nights.
Then I'll fly from Shanghai Pudong to Hong Kong on Jan 22/19, and from Hong Kong to Singapore on Jan 25/19.
I'll come back to Munich on Jan 28/19 flying from Singapore.
I have all the ticket and hotel reservations (obviously the seat are not assigned until the check-in).
Can I apply for 144 hrs free transit?
Should I do anything or contact someone before leaving?