Could you possibly help me out here @Teodor?
This is my current workflow tree:
Works as expected, except the last step (Set Array List Index Properties) is not updating the Item value(s) in the LineItems Array List. How can I fix that?
Tried this setup as well:
That one throws an error: “arraylist.set: index is required.”
I also can’t use “Array List Index of” to get a list of indexes for the items to set a new value for, because “Array List Indexof” only works on text arrays as mentioned on @Hyperbytes‘ amazing tutorial. LineItems is an object array: `"LineItems": [{"title": "Test 123","amount": 24,"quantity": 1,"currency": "eur","totalproductvalue": 23,"totalshippingcosts": 1,"totalamount": 24,"merchantid": 6}]`
So I’m quite stuck here, hoping someone can help me out 
Also, it’s not possible to set an Item’s value to zero in “Set Array List Index Properties”. After saving the field is empty then again. Any other value can be set without issues.
Thanks for your help in advance!