- List the Id's and look for 'ELAN1200: ...' or anything with touchpad mentioned :
xinput list
- Grab the ID and List the properties for this ID (eg: 14) :
xinput list-props 14
- Set the value of the property "libinput Scrolling Pixel Distance" to 50, you can change this value by default is 15, if the value is bigger the acceleration is slower: