How you request it or where you are when you make the request doesn't change the legal status of the record itself if a data set has been made public by your state legislature.
If your local laws say you have to make the request in person, so be it. It's still an open record that can be queried and retrieved by members of the public.
If your local law say you may make your request online at a specific web address, so be it. It is still an open record that can be queried and retrieved by members of the public.
The mechanism or methodology of requesting a public record does not change a public record factually and legally being public unless local law says so (or FOIA if we're dealing with a federal agency, but since the context here is 911 calls, this is much more likely going to fall to a how a state legislature decides to protect/expose public records).