Board Thread:The Last Sovereign Discussion/@comment-29984007-20180410151643/@comment-35006067-20180709055644

Also, StackOverflow offers some workaround, as usual: https://stackoverflow.com/questions/13405129/javascript-create-and-save-file

Basically, it creates a temporary url with a temporary file made of the data of your choice, then the user can use the standard download function of any browser.