Tax collection

Non Syrian here. Could someone explain the tax situation in non government controlled regions, in terms of calculating, collection and enforcement of tax revenue.

For example: does the central government still collect personal and company taxes in areas it doesn't control, and, if so, how does it know how to calculate that tax (some is not controlling that area / city, how does it enforce those payments due when that person or company is living in a city/ region that the central government has no control over?

Another example: when a region or city changes hands, how does the new occupying force calculate taxes due from companies and persons, and how does it enforce the collection of those taxes.

Another example: in a large city like Aleppo that has recently changed hands, how does the new occupying force get access to everyone's personal income and company profit information, and collect the taxes on that income. And, what bank does it deposit the funds in?

Another example: say someone in Aleppo didn't or hadn't paid their personal or company taxes for the year 2022 and 2023 (for whatever reason - valid or invalid). How does the new government of Aleppo know this, and once they find out the person hasn't paid taxes for those years, does it demand payment of those outstanding taxes (even though technically and legally, the taxes belong to the previous government).