From what I can tell it seems that getCurrentPosition is an asynchronous function. Note that this doesn't mean it's declared async or that it returns a Promise object that can be await-ed on.

You can convert your getCurrentLocation function to an async function and wrap the getCurrentPosition call in a Promise.

const getCurrentPosition = (options) => {
  return new Promise((resolve, reject) => {
    return navigator.geolocation.getCurrentPosition(resolve, reject, options))
  };
};

export const getCurrentLocation = async (options) => {
  const location = {
    userLat: '5',
    userLng: ''
  };

  try {
    const position = await getCurrentPosition(options);

    //getting the Longitude from the location json
    const currentLongitude = JSON.stringify(position.coords.longitude);

    //getting the Latitude from the location json
    const currentLatitude = JSON.stringify(position.coords.latitude);

    location.userLat = currentLatitude;
    location.userLng = currentLongitude;

    console.log('lat: ', location.userLat);
  } catch(error) {
    console.warn(error);
  }

  return location;
}

Consuming code:

const options = {
  enableHighAccuracy: false,
  timeout: 30000,
  maximumAge: 1000,
};

const { userLat, userLng } = await getCurrentLocation(options);

As @Drew stated getting the location is happening asynchronously, so that retun is happening before the console log. Another way of talking this is to transform your function to a hook, so you will be able to use useState. Like so:

import { useEffect, useState } from "react";
export const useGgetCurrentLocation = () => {
  const [location, setLocation] = useState({
    userLat: "",
    userLng: "",
  });
  const [fetchingLocation, setFetchingLocation] = useState(true);
  const [error, setError] = useState("");

  useEffect(() => {
    navigator.geolocation.getCurrentPosition(
      (position) => {
        setLocation({ userLat: position.coords.latitude, userLng: position.coords.longitude });
        setFetchingLocation(false);
      },
      (error) => {
        console.warn(error);
        setError("Something went wrong!");
        setFetchingLocation(false);
      },
      {
        enableHighAccuracy: false,
        timeout: 30000,
        maximumAge: 1000,
      }
    );
  }, []);

  return { location, fetchingLocation, error };
};

And you would use it as below. First you would get fetchingLocation containing true, then it becomes false, and whether the location is successful or not, you would get error containing a message or location containing the actual latitude and longitude.

const { location, fetchingLocation, error } = useGgetCurrentLocation();