use pipe and map to transform response in angular code example
Example: observable pipe change one property
getPerons(): Observable<Person> {
this.http.get('url').pipe(map(response => ({...response, age: response.age + 2})));
}
getPerons(): Observable<Person> {
this.http.get('url').pipe(map(response => ({...response, age: response.age + 2})));
}