Is it obligatory to inform friends and acquaintances that the commission for booking airline tickets, which is done outside my official work and from my private account, is for me personally, or is it sufficient to inform them only of the ticket price and the amount of the commission?

If you offer a service outside your official working hours, or during them with the permission of your employer, you are permitted to request a commission from the person you are serving, provided there is no deception or trickery. You must inform the beneficiary that you are requesting the commission for yourself; otherwise, it will be considered deception. If you have not prepared yourself for the work, you are not entitled to a wage, except in cases of saving protected property, returning a runaway slave, or if you have prepared yourself for the work.