Install Adobe on MacBook Air 10.15.4 Catalina

What does "Flash doesn't seem to work with Adobe." mean?

Flash Player works on all supported browsers on supported macOS versions.   See https://www.adobe.com/products/flashplayer/tech-specs.html

With taht said, all browser vendors disable/block Flash by default.  When the browser detects the content requires Flash, the browser prompts the user to enable/allow Flash (assuming Flash is installed). This happens between the browser and the content.  Flash Payer itself is not involved in this communication.

See https://helpx.adobe.com/flash-player.html for information to enable/allow Flash on the various supported browsers.

If that doesn't work, provide the following information:

• browser, including version
• direct link to content that is not working
• detailed description of what happens when you attempt to view Flash content
• screenshot of error, if any, you are getting