What is the ruling on money earned from working in a company that requires the addition of fictitious chemical materials to customer invoices in exchange for a commission, knowing that this is common practice in the company and that refusing to do so may lead to losing one's job?

The aforementioned act is Islamically forbidden (haram) because it involves lying, deception, and unlawfully consuming people's wealth. What is taken as compensation for additional forbidden work is an unlawful earning. As for the original salary, it is permissible (halal) if it is in exchange for a permissible job. It is obligatory to leave work at this company as long as it necessitates forbidden actions, and to seek a permissible job. For whoever fears Allah, He will make for him a way out and provide for him from where he does not expect.