OK! I have understood..

THANK YOU VERY MUCH

Good Morning
I would appreciate if you could clarify a couple of questions I have about your Duet wifi and Duex boards.
I need to use external drivers for 8 motors. Documentation says that I cannot connect the three pins to the controller side for this purpose. Could you explain me why not?
Please note that I also have a duex5 board, but I can not use these drivers for this project, for other reasons.
The motors I want to use have the integrated drivers.
For this purpose, I would not mind to use the Duetwifi controllers for the 5 extruders. However I need a way to drive the other three motors for the axes which already have integrated drivers. Please note that I cannot use the LCD connector for the motors, since I need it for other purposes.
Can I unconnect the pins (step / dir / cs) for each motor used on each axis in the 50-pin connection block and still use Duo / Duex safely?
In addition, I need to connect a 12v and 30W water pump (Model D5 PWM9-38) and computer fans. The pump and the fan have four connectors as the following image:

Where I can connect this pump and fan to duet wifi / duex?

I would appreciate your help on the above.

Thank you!