Is one allowed to give a birthday present to a friend during the 9 days preceding tisha B’av? Thank you

Although giving and receiving presents is not specifically prohibited during the nine days, It is not allowed to aquire new clothed or utensils, so presents would be severely limited. The general instruction that one should limit "simcha" - joyous occasions, suggests that putting off the gift would be appropriate, but not absolutely required, for instance if the friend would not understand.