How to get an Open Work Permit
An Open Work Permit is typically attached to another type of application. For example, an Open Work Permit can be obtained with an inland Spousal Sponsorship application. This Open Work Permit can be issued upon receiving the approval in principle.
Another way of obtaining an Open Work Permit is through the main applicant's work permit. Meaning, the spouse of the main applicant can apply for an Open Spousal Work Permit.
The point is that an Open Work Permit is not something you can have by directly applying for it. It is connected to a main application. If you do not have a main application, then you might need to apply for a Labour Market Opinion first and then obtain your work permit. Though there are even exceptions to this rule as not all intended employment in Canada require a labour market opinion.