I can't find the essays in spanish in the lds website. I wonder if they hide them so well or don't have them at all. Do they have them available in other languages?
AFAIK they were never translated into Spanish. From the church's perspective, it was bad enough that the essays existed at all, and so there was zero incentive to make them accessible to more people.
Article of Faith 14: We believe the Church essays as far as they are translated correctly and if the timing of such information is convenient to the narrative of the church corp. Let them not read if it will destroy a testimony how, when or where it might cause them to stop paying tithing.