Simply Static - GitHub send Webhook with Authentication

functions.php

<?php

add_filter( 'ssp_webhook_args', function( $args ) {
	// Get access token.
	$options       = get_option( 'simply-static' );
	$acccess_token = $options['github-personal-access-token'];

	// Modify arguments for POST request.
	$args = array(
		'headers' => array(
			'Authorization' => 'token ' . $access_token,
			'Accept'        => 'application/json',
		),
	);
	return $args;
});