Changing Font material variables in script

OK so if you make a TextMeshPro Text and go down to the material it shows the font material ( for me Liberation Sans SDF ) and if you go under debug settings and Gradient Scale then messing with the value of it can make a really nice code looking thing on the screen. Anyway I was trying to make an animation for the Gradient Scale but apparently you cant change materials in antimations as it didnt show up despite my efforts. I then tried to edit in code by referencing a material but I was unsure how I would go about adjusting the Gradient Scale variable of the material in script or animation ; the only way I could find to adjust the Gradient Scale was to do so in the inspector. Could anyone help me with this?