- What version of macOS are you using?
- What version of Keyboard Maestro are you using?
It's good to provide this info when asking for help, because it can sometimes make a significant difference in getting a problem solved. The following macro makes this simple:
Paste Keyboard Maestro Version and macOS System Version
- What browser are you trying to switch to?
It looks like you're using macOS Monterey or Ventura. (I'm still using Mojave, so I'm unable to test here.)
Apple decided to get cute with the share sheet and make it look like iOS, so KM's Select menu action doesn't work properly with it anymore.
Does the keyboard work with it?
I.e. can you type-select to get to items in the share sheet?
If so then type-select is your friend. If not then perhaps Click at Found Image
The simplest way of doing this is going to be to use the FrontBrowserURL token to acquire the URL of the frontmost browser (Safari or Google Chrome) and then send that off to the browser you want to open it in.