title: How to add a new increment Field Value in my documents in Firestore?
body: <p>I have a collection in Firestore with several documents in it and I wanted to know if it is possible to add one Field Value (e.x called index) and the value of this value is an increment from 0 to the length of the collection, having the first document &quot;INDEX&quot; : 0, second &quot;INDEX&quot;: 1 and so on until it reaches the last document.</p>