Car door driver side has to be opened from outside

It sounds like you have an inner door handle cable or handle that has broken or come undone. You will need to remove the door panel to take a look. Here is a guide to help you see what you are in for when doing the job

https://www.2carpros.com/articles/door-panel-removal

Here is what it will be like for your car (below)

Please let us know what you find.

Cheers

One of two things the wiring to the mechanism is open or the door lock actuator is bad. My money is on the driver door lock actuator. We see these actuators go out more frequently because the LF or driver is used much more that any other door. This Fusion isn't very old so I would say the wiring is not open.

Here is a diagram on where the lock actuator is (below)

It is fairly simple to do just make sure you take pictures of how it looks before removing. It would be better if you have someone mechanically inclined.
A condensed repair procedure goes like this:

Raise power window to the up position
Remove driver door panel, Disconnect electrical connectors and cable to LF door
Remove weather seal
Disconnect the actuator mounting screw (three on the side of the door)
Disconnect the rods from the door and actuator
Disconnect electrical connector from actuator
Remove from door
Install is reverse of the above.

Hope this helps!

Let me know if you have any more questions, TY

Your welcome