

Someone would need to get that data out of the app. Either as GPX or some other format. I do not think these devices are able to send the position to some configurable endpoint. A quick search for nut tracker and home assistant does not yield any reasonable results.
I think we are out of luck at that point. But maybe someone knows about a more open tracker device which could be configured.
To change the password and the user of the db you have to change it in the postgis service but also need to let reitti know that it is not the standard anymore. You need to set the environment for reitti according to the Readme
If you want to start from scratch you probably need to delete the volumes from docker. See here
Normally the volumes are called reitti_postgis and so on.
Let me know if you need further assitance, i am currently on mobile but can provide more info later