& terminates the command. Escape it or add space after & to silence.curl https://www.google.com/search?q=cats&tbm=ischcurl "https://www.google.com/search?q=cats&tbm=isch"An unescaped and unquoted & terminates the command, but here it's used in the middle of what would otherwise be a shell word. This most commonly happens when copying a URL with query string parameters without escaping the &.
Either quote or escape the & if you wanted it as a literal ampersand, or add a space after it to make it easier to see where the previous command stopped.
If you do want to background one command and run another, e.g. sleep 10&wait, just add a space or linefeed after the & to make this more obvious: sleep 10& wait
This does not change the meaning of the script, it just makes it clear to ShellCheck (and other humans) that the & isn't supposed to be a part of the shell world.
ShellCheck is a static analysis tool for shell scripts. This page is part of its documentation.