Help with the HTTP request node

You could try something like this in a function node (untested as not near my PC)...

msg.url = "https://webhook.site/330debe9-0f95-4805-a766-09cace553fcb";

msg.payload = {
    login: "login_dl",
    password: "password",
    type: "import",
    really: 1,
    content: `<active_item/><new_item/><stationname.short>apiKeyPROTO</stationname.short><message><item.artist>testArtist</item.artist>+-+<item.title>meTitle</item.title></message>`
};

return msg;