What is the ruling on tax evasion and aiding it, and how can an accountant demand his rights from a Sharia perspective after being dismissed and deprived of his dues for refusing to falsify accounts for tax evasion?

Taxes are of two types: permissible, which it is not allowed to evade, and unjust, such as that taken without right, which it is permissible to avoid. And it is permissible for the worker to demand his right and what he incurs in that path.