You can do separate requests from one pipe like that:

return this.upload(myForm).pipe(
  take(1),
  switchMap(res => {
    body.user.profilePic = res.data.profilePic;
    body.user.coverPic = res.data.coverPic;

    return [
      this.http.post<IRresponse<object>>(environment.api + EndPoint.CreateUser, body),
      this.http.post<IRresponse<object>>(environment.api + EndPoint.CreateUser, body),
    ]
  }),
  mergeAll(),
);

The right operator depends on whether you want to send the two request in parallel or consecutively.

If you already have take(1) then you can use both switchMap or mergeMap because it will always emit only once and thus it doesn't matter in this case.

Sending requests in parallel:

return this.upload(myForm).pipe(
  take(1),
  switchMap(res => {
    ...
    return forkJoin([
      this.http.post<IRresponse<object>>(environment.api + EndPoint.CreateUser, body),
      this.http.post<IRresponse<object>>(environment.api + EndPoint.CreateUser, body),
    ]);
  }),
);

Sending requests in sequence:

return this.upload(myForm).pipe(
  take(1),
  switchMap(res => {
    ...
    return concat(
      this.http.post<IRresponse<object>>(environment.api + EndPoint.CreateUser, body),
      this.http.post<IRresponse<object>>(environment.api + EndPoint.CreateUser, body),
    );
  }),
);