How can I atone for taking extra money from my work as an accountant in the hospital's reception department, and for replacing invoices with higher amounts with others of lower amounts to benefit from the difference, knowing that my financial ability to repay was not always available, and now I have the means to do so?

The accountant and the cashier are entrusted with funds, and they must safeguard this trust, for Allah the Almighty says: "Indeed, Allah commands you to render trusts to whom they are due" and "Do not betray Allah and the Messenger or betray your trusts." Issuing fictitious invoices to obtain funds from the entity is an act of betrayal and consuming wealth unlawfully, and it is forbidden, for Allah the Almighty says: "And do not consume your properties among yourselves through falsehood." It is obligatory for whoever has done this to repent, return what they took to the treasury, and resolve never to revert to such an act. As for the excess funds at the end of the working day, this has been addressed previously in Fatwa No. 59095.