//your-service-class.ts
import { QueryBuilderService } from '@kachit/ngx-api-query-builder';
import { HttpClient } from '@angular/common/http';
import { map } from 'rxjs/operators';

let qb = new QueryBuilderService();
let http = new HttpClient();
let params = qb.eq('active', true).build();

let url = 'http://api.your-domain.com/foo';
let data = http.get(url, {params: params}).pipe(
    map((response) => { return response.data})
);