1 rotation from stepper motor needed

[KoenVoortman]

Hi, noob/novice MQTT and Arduino user here.

I have a Homebridge installation with an embedded MQTT broker (Aedes) and a Mqttthing plugin for devices.
That part is working, and I have connection with my NodeMCU and I can control the stepper motor.

I'm in the Netherlands and have Veneta 50mm horizontal/venetian blinds.
I've re-designed a housing for the stepper motor, driver, NodeMCU and power converter, that will fit in the blinds housing, see pictures below.

My problem is: the full open to closed is 1 rotation of the hexagon axis in the blinds housing.
Currently the motor rotates 4 times.

How/where do I adjust settings in the code, so the stepper motor will only rotate 1 time (1x 360 degrees) when I send a 0<->100 command?
I've played with the settings in the Arduino code, and there are limited options in the MQTT code in Homebridge.

I hope somebody can help!