Found something:
Probably Twan just needs to put the word location after ?tag= in the URL:
https://webhook.homey.app/640xxxxxxxxxxxxxxxxx/twan?tag=location
Then selectable location parameter options should appear somehow 
Just like the example with “aangepaste datum”
Full explanation:
(Pls read “webhook”, or “http request”, for their phrase “API request”)
So for the people using Tasker on an Android.
The task:
HTTP Request
Method:
Post
URL:
How i get the coords from IOS
Open Shortcuts or Opdrachten
Create a shortcut : Gps 1
then the follow shortcut
after the 300 seconds card also add a card : open shortcut GPS2
Duplicate Gps1 to Gps 2 and change there the last step to Gps 1
so you create a loop where every 5 minutes the coords will send to homey
Great.
Now the howto is complete 
Hi, I have added the app, installed the API key succesfully, but do not see any “then” cards when creating a flow. What am i doing wrong?
Since they return tags homey has limited them to advanced flows only
Hi Helmut, I tried the same shortcuts but it seems like if the phone is locked the loop stops and Homey does not receive updates. I set the delay to 180 sec but nothing. If I try while the phone is unlocked it works.
Do you have the same issue?
I checked and both the shortcuts have the permission to run with locked screen.
The same issue here…i think it’s Apple limitation to protect the battery life.
