Unfortunately, if you have already e-filed your state return, you would not be able to make changes to a pending return. If you need to amend your return, you would need to wait until it's either been accepted or rejected. If it's rejected, you can simply go in and fix the error and re-submit your return. If it's accepted, you would want to wait until you receive your refund and then use the link provided below to make sure you really need to amend:
Do I need to amend