I just updated to Catalina but The Sidecar option does not apear in the Systems Prefference menu. What can I do access Sidecar

Does your Mac and iPad meet these requirements?

Sidecar

Supported by the following Mac models:

• MacBook (2016 or newer)
• MacBook Air (2018 or newer)
• MacBook Pro (2016 or newer)
• Mac mini (2018 or newer)
• iMac (late 2015 or newer)
• iMac Pro (2017 or newer)
• Mac Pro (2019)

Supported by all iPad models with Apple Pencil support:

• 12.9-inch iPad Pro
• 11-inch iPad Pro
• 10.5-inch iPad Pro
• 9.7-inch iPad Pro
• iPad (6th generation or later)
• iPad mini (5th generation)
• iPad Air (3rd generation)

It's a Macbook Air 2017, so I guess not. Is there any way to make sidecar work?

I posted the requirements. Not sure why that is a question. Whatever hardware is required you don't have.