although barbell press is not a good exercise for shoulder safety if you want to do it, at least do it the way that has minimum risk. no matter where you put your hand, either your wrist, elbow or shoulder is going to be in a bad place, and since the shoulder is a lot more vulnerable compared to others, it is better to shift the pressure more on the other joints than this, so make sure the elbow is between 70 to 30 degrees(horizontal abduction/adduction) and do not extend it too much and do not flex it too much. make sure you perform it in front of the mirror to check whether the bar is traveling symmetrically or not.