Expandable Window Screen：1 Pack Adjustable Window Screen Replacement (10" H x 14.3" - 26" W) - Extra Small Replacement Window Screens with Frame Expandable,Aluminum Horizontal Sliding Window Screens

https://www.amazon.com/Expandable-Window-Screen%EF%BC%9A1-Adjustable-Replacement/dp/B0FRNF3LP8 look in amazon for 'adjustable window screen', lots of choices whichever you get, make sure it's very securely placed