Sidlo
A sidlo is a registered address for a business.
In order to have a business in teh CZech Republic you will need and address inside the country at which to register your business. You must have a business address at which the owner can be contacted.
There is no exception to this law.
If you wish to own a Czech company (an S.R.O.) you need to have premises at which to register the company address. Without that, you cannot register a company.
The address for a business can be anywhere in the Czech Republic.
Temporary business address
It is possible to use a temporary address whilst setting up the company and then "move" the company to a different address at a later date.There are plenty of companies offering this kind of service, that can be found on the internet, through a simple search.