How to add relay domain to Hiddify manager

https://github.com/hiddify/Hiddify-Manager/wiki/%D9%86%D8%AD%D9%88%D9%87-%D8%A7%D9%81%D8%B2%D9%88%D8%AF%D9%86-%D8%B3%D8%B1%D9%88%D8%B1-%D9%85%DB%8C%D8%A7%D9%86%DB%8C-%D8%A8%D9%87-%D9%87%DB%8C%D8%AF%DB%8C%D9%81%D8%A7%DB%8C-%D9%85%D9%86%DB%8C%D8%AC%D8%B1