Numbers in sequence saved in firebase

Hello everyone

For a few days I’ve been trying and unsuccessful trying to save numbers in ascending order in frebase as tags, someone could help me.

Just to make it better explained, what I want is to save the number as a tag to be able to control how many numbers were distributed, the saved value would be the name of the user of the app.

follows the prints of the firebase template and my blocks that are not working


Screenshot_3 !

Once you have the last item, you can then do your +1