What do you see in the console in your modeler? You can indeed call a microflow when clicking a button and changing the attribute within the object with $Object/attribute + 1.
You can have the default value as desired. However you have to check whether the value is empty (when this can occur). So in your change add something like: if $Object/attribute = empty then 1 else $Object/attribute + 1
I fixed the error, turns out that the database had a constraint with the integers to be always 0 when I chose to auto fill then in the data view
These are screenshots of my software and the microflow it self.These are screenshots of my software and the microflow it self.