You cannot list the pages that Google should visit in the robots.txt file. That's the file where you list the pages web crawlers, like Google's GoogleBot, are NOT allowed to visit – it's the exact opposite of what you are describing. Beyond that, I can open your site's robots.txt just fine from a browser, wget, and curl.
You explicitly list page crawlers should visit in a sitemap.xml file. If I try to instead visit the sitemap.xml URL on your site I get a 403, not a 500. If that's what you meant, it's easy to fix with a new line simply reading sitemap.xml in the .htaccess Maker's "Allow direct access to these files" – and click on Save and Create .htaccess, of course, to apply the change.
If you mean something different, please switch to German and describe exactly what you're trying to do and where exactly you get the 500 error. Sure, English is preferred – especially in public tickets – because I can only comfortably read English and Greek, and other people seeing the public ticket will most likely only have English as their common language with us two. However, if the choice of language gets in the way of actually communicating the issue you want help with I am fine with you using whichever language you are comfortable with. I have local AI models which cover about 200 languages and even more dialects; I can use them to translate tickets in literal seconds. I am even considering removing the "English only" rule from support now that I've used those tools and they've proven to be extremely reliable (unlike Google Translate and similar translation services from the pre-AI era).
Nicholas K. Dionysopoulos
Lead Developer and Director
🇬🇷Greek: native 🇬🇧English: excellent 🇫🇷French: basic • 🕐 My time zone is Europe / Athens
Please keep in mind my timezone and cultural differences when reading my replies. Thank you!