What is the ruling on money acquired from a fictitious job before knowing of its prohibition, and after knowing of it, if the pharmacy owner forgives this money and refuses to remove the fictitious name?

There is no harm in money earned before knowing the unlawfulness of a transaction. So, whoever engaged in a forbidden transaction out of ignorance and then ceased it upon realizing the ruling, "he may keep what is past," just as in the case of usury.

It is not permissible to take money as compensation after knowing the ruling, and the pharmacist's forgiveness is irrelevant if it is in exchange for this transaction.

It is permissible to remain as a manager without compensation to prevent harm. If he gives money willingly, not as a form of exchange, then there is no objection to accepting it.