Accessing a weather API through current location

Im currently building a simple weather app, I have a service set up take data from open weather API, take in current location coordinates via geolocations in the home page.ts and want to be able too sub them in for {lat} and {lon} into the API url so it pulls weather from you current location, and I am unsure how too go about doing this,any help would be appreciated

this is the service.ts file

import { Injectable } from ‘@angular/core’;
import { HttpClient} from ‘@angular/common/http’
import {Observable} from ‘rxjs’
import { Geolocation } from ‘@ionic-native/geolocation/ngx’;

providedIn: ‘root’

export class WeatheredataService {

constructor(private httpClient: HttpClient) { }

public getWeather():Observable{

return this.httpClient.get('{lat}8&lon{lon}&appid=fec30507acb533f670080ab3174f226f')