unexpected 'use' (T_USE) when trying to use composer

This error message is indicating that there is an unexpected use of the keyword "use" in your code when trying to run Composer. This error can occur for a variety of reasons, such as a syntax error in your code or a problem with the version of PHP you are using.

One common cause of this error is that you have a PHP version that is too old. Composer requires at least PHP version 7.1.3. Make sure your version of PHP is up to date.

Another cause of this error is that you have a syntax error in your code, such as a missing semicolon or unmatched parentheses. Check your code for any syntax errors and fix them.

If the error persists, it may be helpful to check the version of composer you are running and update if necessary.

Lastly, you can try running the command composer diagnose to check for common problems and try to fix them automatically.