Ipad Air 3

Here:--> https://www.apple.com/shop/ipad/accessories/cases-protection?page=1&f=caseios-ipadair2019&fh=4583%2B4b33%2B45d1

or, specifying "for iPad Air 3rd generation 10.5", on other e-commerce websites.

Regards

Giulio

Here is one such case from a case company I absolutely love, called Zugucase.

Here is their case for your 2019 iPad Air 3 model.

https://www.zugucase.com/products/2019-ipad-air-3-2017-ipad-pro-10-5-case-prodigy-x

Plenty on Amazon.com

Search 2019, 10.5 inch screen iPad Air 3 cases ( these cases will also fit the 2017, 10.5 inch screen iPad Pro models, as well ).

Best of Luck to You!