app/Providers/AppServiceProvider.php

@@ -15,7 +15,11 @@ class AppServiceProvider extends ServiceProvider {
 	 */
 	public function boot()
 	{
-		//
+		// Force HTTPS URLs when behind a proxy (Traefik)
+		if (isset($_SERVER['HTTP_X_FORWARDED_PROTO']) && $_SERVER['HTTP_X_FORWARDED_PROTO'] === 'https') {
+			\URL::forceSchema('https');
+		}
+
 		Blade::extend(function($value) {
 			return preg_replace('/\@define(.+)/', '<?php ${1}; ?>', $value);
 		});

docker-compose.yml

@@ -16,6 +16,7 @@ services:
       - PROD_PRIVATE=${PROD_PRIVATE}
       - IMAGES_URL=${IMAGES_URL}
       - UPLOAD_URL=${UPLOAD_URL}
+      - FORCE_HTTPS=true
       - MAIL_DRIVER=${MAIL_DRIVER}
       - MAIL_HOST=${MAIL_HOST}
       - MAIL_PORT=${MAIL_PORT}