Is it permissible to amend an item in a raise request without informing the manager, after the manager refused to cancel it, and after problems arose from this item with negligent colleagues?

It is not permissible to change any clause of the agreed-upon contract without the permission of the authorized official, in fulfillment of the contract's terms and in adherence to what the two parties agreed upon. Allah Almighty says: ﴿O you who have believed, fulfill [your] contracts﴾ [Al-Ma'idah: 1], and the Prophet, peace be upon him, said: "Muslims are bound by their stipulations." If the bonuses official is authorized and accepts the change, then there is no harm. However, if this is the responsibility of the general manager, then it is necessary to refer to him and explain the matter to him. If he agrees, then that is good; otherwise, you are not permitted to change it. You either accept it and act in accordance with it or reject it, for the contract is the law of the contracting parties.