The business licence process exists so the City of Saskatoon knows the unit meets basic safety and zoning requirements, and it must be renewed on a regular schedule rather than obtained once and forgotten. A licence can be suspended or revoked for repeat bylaw complaints, which is a real cost if the property was purchased partly for its rental income.
A title search by a lawyer, part of the standard $800 to $1,500 legal fee range for a purchase, is the way to catch a restrictive covenant before you buy a property specifically for short-term rental use, since that kind of restriction does not show up in listing photos or a City licence lookup alone.
Confirm the licence requirement and the title before you plan a purchase around short-term rental income, not after you already own the property. Get your hand-reviewed valuation from Joel Dyck.