My conclusion: as shown in the Shimano instruction, it is definitely not: just press with by hand: no chance !!!
I then gently (!) Tried force with pliers. Again, I was not able to close the Quick-Link. One would have to the chain link during the chain already on the wheel is neat turn, so that the perforated metal snaps. More power, I did not use, because in another forum a user had therefore already damaged the chain. Then I with the BBB chain lock which has naturally increased the price of the chain to 1.5 times, the chain in less than 30 seconds closed. That's how it should be.
This included closing is just plain cheaper scrap. That should be a company like Shimano does not allow, so 2 star deduction.