It is normal that the leader will not invite subordinates to celebrate together on his birthday. Of course, it is not ruled out that he will take this opportunity to get closer to everyone. If you want to give a gift, you must understand the leader's temper. Don't give a bad gift, which will make it look bad. Here are some small suggestions:
1. You can give some simple friendship gifts, such as the current bestsellers, or a box of slightly better tea, which are all good.
2. Of course, if you are a careful observer, you can pay attention to the leader's preferences and what he likes in normal times, and you can give him such a surprise on his birthday.
3. Discuss with colleagues and see if you can give a larger gift to the leader together, so as not to leave anyone behind.