Hello and welcome to the Node-RED forum.
This might help to get you started. A very simple flow using UI components.
Enter your values (start and increment) in the form in the UI, then click submit.
Each time you click 'Trigger_the_node' it should increment after showing the initial value.
i.e. It outputs the current value, then increments the value as per your stated requirement.
There are probably lots of other ways to implement this - as people will probably tell you.
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