Use either of these two, and cut it to fit.
https://www.amazon.com/MoKo-Protector-Nintendo-Anti-Fingerprint-Anti-Bubble/dp/B06XC5JQ8V/ref=sr_1_8?dchild=1&keywords=nintendo+switch+screen+protector+plastic&qid=1601939938&sr=8-8
https://www.amazon.com/gp/product/B06XB8LGJX/ref=ewc_pr_img_2?smid=A10ABS3Q8PD59I&psc=1