If you want to use Basic Auth while using get_headers(), use stream_context options below.
I am using HEAD method here, but please feel free to use GET also.
<?php
$targetUrl = 'http or https target url here';
$basicAuth = base64_encode('username:password');
stream_context_set_default(
[
'http' => [
'method' => 'HEAD',
'header' => 'Authorization: Basic ' . $basicAuth
]
]
);
$result = get_headers($targetUrl);
print_r($result);