I am trying to download a .xls when I click a button on my website for this it is loading another page with

header("Content-type: application/vnd.ms-excel");

in the php file

I am also using certain libraries to generate the text that is to be presented in the xls file

echo "<script src = '.....'></script>"

When I remove the header part then the data is presented correctly in the browser but with the header I sometimes get the error "missing files <relative path added to my Downloads folder>", but the text is never present in the xls file which I am generating using the external javascript files

I believe when downloading they make the downloads folder the root and want all the external files to be present on my computer instead of the server

How can I work around this? Thank you