TN visa to H4EAD


Currently i am working on TN visa. My TN visa and H4 visa got approved in difference of 1 week in 2016. Last month traveled outside USA, my updated i-94 still should H4 information. My husband’s i140 got approved in April. i want to apply for H4EAD . as per records my H4 is still valid. Can i still go ahead and apply for H4EAD, if yes how?