Is a translator's request for 2% of the project's value in exchange for assistance in completing procedures—after the tender was awarded to the contractor without his intervention—considered a bribe or extortion, especially since there was no prior agreement on this?

If the translator is an agent for following up on the tender, then the basic principle of agency is that it is without remuneration unless there is a condition or custom [to the contrary]. If it is customary to pay a percentage or the customary fee to the agent, then it is obligatory to pay it to him. And since the translator has exerted effort, he should be compensated for his work, even if it is not obligatory, and this is not considered a bribe.