If you want something, you have to take it how you can get it. Not how you prefer to get it.
The insurance test is not learning rocket science. And you will learn just enough to know that you still know nothing about insurance after the classes/exam. The real learning comes after the insurance exam.
If you can afford to not have income for a few months... in order to take a test that you might not even pass... in order to get hired at a firm that might not even hire you... then go for it. If not, take the online class.
What scagnt83 said...
If your current job doesn't afford you the PTO to take the course, then take 3 days of unpaid leave vs. forfeiting income for an indefinite amount of time. Sometimes gaps in employment are understandable, this one isn't one of those times.