How to use http delete () in Angular 6

What about defining your post_jobs_id in your url? And after that get the id in your backend.

For example, you can define :

DeleteRequestToAPI(post_jobs_id:string) {
    const url = `http://127.0.0.1:8000/api/employer/post_jobs/${post_jobs_id}`;
    return this.http.delete(url, {
        headers: new HttpHeaders({ 'Content-Type': 'application/json' })
    })
    .map(this.extractData)
    .catch(this.handleError);
}

there is no body argument on delete.

so, you need to remove body argument.

this.http.delete('http://127.0.0.1:8000/api/employer/post_jobs/',options)

Reference

class HttpClient {
     delete(url: string, 
       options: { headers?: HttpHeaders | { [header: string]: string | string[]; }; 
       observe?: HttpObserve; params... = {}): Observable<any>
}

Edit: How can I pass post_jobs_id?

you can use HttpParams:

let httpParams = new HttpParams().set('aaa', '111');
httpParams.set('bbb', '222');

let options = { params: httpParams };

this.http.delete('http://127.0.0.1:8000/api/employer/post_jobs/',options);