What does ETA means when request API access from a company

I was requesting API access to Changelly.com (A cryptocurrency exchange platform) for use on my platform (website) and they are request for something called ETA, i have no idea what it means and cant seem to find anything on google. I have tried to look it up on their website and API documentation but doesn't seem to find anything helpful. Already mailed them back and no response yet. Anyone knows what it might mean. I was guessing 'Estimated Time of _______' . Although i found something interesting online while searching but not too sure if it's what i am looking for here is the link 4 Types of Enterprise Architecture