You can buy keyboard covers for it, older laptop use to get them in the box.
Riley said:
You can buy keyboard covers for it, older laptop use to get them in the box.
This doesn’t provide any solution for the question asked! 
You can’t, those marks are the result of debris/dust being rubbed between your screen and keycaps making the surface of the screen scratched
I’ve also had this issue on my now-replaced Asus TUF laptop, never had them before and haven’t had them for 2 years without using any protective covers on my current Lenovo laptop.
And, you can’t really get them off, best thing to do is try not to let it get worse.
@Leighton
Why does this happen tho?
Asus keys might be designed to stand a bit higher off the base so they touch the screen more easily, plus I would say you got dust under the keycaps and when moving the laptop, dust comes out from under them, touches and scrapes the screen.
It seems like dust is tiny so it shouldn’t do something like that, but give it enough time and it will.
Good luck!
It is a design flaw. In the constant search to make an item smaller and thinner and sleeker, manufacturers place the keyboard closer to the screen. Now many laptops the screen is very flexible and when you carry it you can form the top very slightly and the screen makes contact with the keys. 20-year-old laptops or more never had this problem because they left adequate space between the key tops and the screen Plus the screens were not as flexible much more rigid. In a properly designed laptop you should not need a microfiber or other cloth between the screen and the keyboard but unfortunately in this day and age you do.