Solve an issue related to location in ios app made with Flutter

We have an app that does the following. It was created with Flutter
1. It updates the current location to the server every 2 minutes and it does even if the app is in the background
The issue is that after some time, the app stops sending the location to the server. I suppose the app is put to sleep by the OS, or something else happened. I have to include that when the app is minimized or put to the background, it pushes the location every 2 minutes for like 40 minutes, and then it stops. We have to bring the app to the foreground for it to resume its work.
We are using a library called location– https://github.com/Lyokone/flutterlocation/tree/master/packages/location

We are ok if the accuracy is not very precise and the update could be sent every 5 minutes instead of 2.
If you have experience around ios and location then please bid. We are open to using other kinds of solutions if they solve our issue. Please note that we will need to use Flutter and if you plan to solve by writing native code, we need to call that from Flutter, maybe I can help you with that.
I will give access to the code once we are on the agreement terms.
please also mention how you are planning on solving this.