The bill to fund the move was passed into law by the congress and senate, but it was the policy of the government at the time and successive governments until now to not act upon it.
So while there was a provision to move the embassy, it has not been policy of a sitting government until now.
It's probably not going to happen anyway. Trump just used this as a campaign promise to stir up part of his his base, evangelical christians, who are grossly uninformed when it comes to what the State of Israel is and what it does. He has acted upon it because it's actually a promise he can keep, or at least be seen to attempt to keep. Unlike building a wall that will be paid for Mexico, all the coal and manufacturing jobs that will never materialize, the budget being balanced, appointing a special prosecutor to "lock her up" etc, etc.