File not downloaded as attachement on browser although api return file

I work on asp.net core 2.2 web api project with angular 7 .

my issue on when click on upload button

File not download as attachment on browser .

when put break point on api and run angular app it hitted break point and file name can see from api when pass it

I think this is problem of angular 7 because web api return file

on angular 7

on angular 7
component.ts
fileToUpload: File = null;
public uploadFile = (files) => {
const formData = new FormData();
formData.append('file', this.fileToUpload,this.fileToUpload.name);
this.http.post('https://localhost:44396/api/ApprovalQuality/', formData)
.subscribe(data =>{
}, error => {
console.log(error);
});
}
handleFileInput(files: FileList) {
if (files.length == 0) {
return;
}
this.fileToUpload = files.item(0);
console.log(this.fileToUpload)
}
component.html
<button type="button" class="btn btn-success" (click)="uploadFile(files)">Upload Filebutton>

test api return like that by post man give me 200 Status OK

but on browser no file download as result

when connect angular 7 with api no file returned and no file downloaded

so How to solve issue