Use arduino to control the throttle of a 72V Infineon controller and 2Kw BLDC

Hi Guys,
I am working on an e-bike project which uses a 70V battery, a 12fet Infineon controller as well as a 2kW Brushless DC motor. I tried yesterday to send throttle commands directly to the ESC using the arduino analog PWM output but the motor was responding through impulses and not a continuous rotation at all throttle levels. I am assuming this is due to the fact that a throttle input is continuous whereas the arduino analog output is a PWM. What could I do to solve this pb?
Thank you in advance for your help!

Can you post a link to the controller? Brand? Part number? What command voltage is required, 0 - 5V, 0 - 12V ?