Angular: How to download a file from HttpClient?

Try something like this:

type: application/ms-excel

/**
 *  used to get file from server
 */

this.http.get(`${environment.apiUrl}`,{
          responseType: 'arraybuffer',headers:headers} 
         ).subscribe(response => this.downLoadFile(response, "application/ms-excel"));


    /**
     * Method is use to download file.
     * @param data - Array Buffer data
     * @param type - type of the document.
     */
    downLoadFile(data: any, type: string) {
        let blob = new Blob([data], { type: type});
        let url = window.URL.createObjectURL(blob);
        let pwa = window.open(url);
        if (!pwa || pwa.closed || typeof pwa.closed == 'undefined') {
            alert( 'Please disable your Pop-up blocker and try again.');
        }
    }

Blobs are returned with file type from backend. The following function will accept any file type and popup download window:

downloadFile(route: string, filename: string = null): void{

    const baseUrl = 'http://myserver/index.php/api';
    const token = 'my JWT';
    const headers = new HttpHeaders().set('authorization','Bearer '+token);
    this.http.get(baseUrl + route,{headers, responseType: 'blob' as 'json'}).subscribe(
        (response: any) =>{
            let dataType = response.type;
            let binaryData = [];
            binaryData.push(response);
            let downloadLink = document.createElement('a');
            downloadLink.href = window.URL.createObjectURL(new Blob(binaryData, {type: dataType}));
            if (filename)
                downloadLink.setAttribute('download', filename);
            document.body.appendChild(downloadLink);
            downloadLink.click();
        }
    )
}