Unable to retrieve query string parameter value by using Laravel 5.6

Question

I am unable to retrieve the query string parameter value from the URL. My project is running in sub-directory.

Please find the following details about my code

**Request & result ** http://example.com/api/institutes/search?searchValue=hello-world

.htaccess

<IfModule mod_rewrite.c>
    <IfModule mod_negotiation.c>
        Options -MultiViews
    </IfModule>
    RewriteBase /

    RewriteEngine On

    RewriteCond %{REQUEST_FILENAME} -d [OR]
    RewriteCond %{REQUEST_FILENAME} -f
    RewriteRule ^ ^$1 [N]

    RewriteCond %{REQUEST_URI} (\.\w+$) [NC]
    RewriteRule ^(.*)$ public/$1

    RewriteCond %{REQUEST_FILENAME} !-d
    RewriteCond %{REQUEST_FILENAME} !-f
    RewriteRule ^ server.php

    # Handle Authorization Header
    RewriteCond %{HTTP:Authorization} .
    RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}]

    AllowOverride All
</IfModule>

Route Route::get('/institutes/search', 'InstituteController@search');

Controller:

public function search(Request $request)
    {
        try {
            $searchValue = 'Search value: ' . $request->searchValue;
            return $searchValue;
        } catch (Exception $e) {
            return response()->json(['error' => $e->getMessage()], 500);
        }
    }

Result: Search value: