Welcome to the community.
Have you done this tutorial
How to broadcast a GPS location and share the information on a map with others in real time..CloudDB ?
Part of what you need to do might be covered somewhere in the tutorial.
or perhaps this this example: Social Distancing ... a CloudDB / Location Marker Tutorial
It seems what you might need to do is accumulate a List of geocoordinates and store them (in a TinyDB or in the CloudDB itself, then post the locations on a Map using a runtime Marker . The basic required code would look something like this::
What you do depends on what you already coded and whether you add coordinates using the LocationSensor or by capturing them by touching the Map.
Here is a tutorial showing essentially how it can be done using a Google sheet and an extension; however you do not need the extension as mentioned in the tutorial. All can be done with the regular LocationSensor in a similar fashion ... see HOW TO: use LocationService extension Version 1 and Version 3 with a GoogleSpreadsheet to record real time locations while the app is in the background