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[Help] How can I read from a component and update it right once

I have a page number want to display. I have a next page button. when user push next page button. I need to get Input from the componant value of page number and plus 1 then Output back to it with callback.
I tried to make it as below:
@app.callback(
[Output(‘page_no’, “children”)],
[
Input(‘btn-prev’, ‘n_clicks’),
Input(‘btn-next’, ‘n_clicks’)
],
[State(‘page_no’, ‘children’)]
)
def update_page_number(n_clicks_prev, n_clicks_next, page_index):

but I got an error:
Multi output …page_no.children… contains an Output object
that was already assigned.
Duplicates:
{‘page_no.children’}

is it possible to achieve this kind of case with cash? read componant value and then update it.