DAS is only available at Guest Relations at one of the 4 Theme Parks.
The outside of the park Guest Relations sites occasionally are not able to issue DAS. It’s usually either because they are too busy with guests with ticket issues that need to be resolved before they can enter the park or because they don’t have the iPad that is needed to issue DAS. Both of those are more likely early in the morning.
Another thing to be aware of - you can see into the park entrances from all of the outside of park Guest Relations. That’s not an issue for some people, but a big concern for others.