CORS Error: What is the correct way to configure Symfony 5 to accept CORS?

After struggling with nelmio for a while, I found it easier to go with this ghetto solution:

public/index.php:

if ($_SERVER['APP_DEBUG']) {
    header('Access-Control-Allow-Origin:'.rtrim($_SERVER['HTTP_REFERER'], '/'));
} else {
    header('Access-Control-Allow-Origin:yourdomain');
}
header('Access-Control-Allow-Headers:*');
header('Access-Control-Allow-Credentials:true');
header('Access-Control-Allow-Headers:X-Requested-With, Content-Type, withCredentials');
if ($_SERVER['REQUEST_METHOD'] === 'OPTIONS') {
    die();
}

I use this just after the bootEnv line. I'm using symfony 5+

Hi could you try changing the path from '^/' to '^/api/' in NelmioCorsBundle and add this configuration like this example:

nelmio_cors:
    defaults:
        origin_regex: true
        allow_origin: ['%env(CORS_ALLOW_ORIGIN)%']
        allow_methods: ['GET', 'OPTIONS', 'POST', 'PUT', 'PATCH', 'DELETE']
        allow_headers: ['Content-Type', 'Authorization']
        expose_headers: ['Link']
        max_age: 3600
    paths:
        '^/api/':
            allow_origin: ['%env(CORS_ALLOW_ORIGIN)%']
            allow_headers: ['X-Custom-Auth', 'Content-Type', 'Authorization', 'Location']
            allow_methods: ['POST', 'PUT', 'GET', 'DELETE', 'OPTION']
            expose_headers: ['Link', 'Location']
            max_age: 3600