@christinebetts "I tried adding it as a contribution amount but it did not seem to get added into the Net Pay total on the payslip, so did I do something wrong?"
Unless they changed the terminology in QBO, contribution amounts typically refer to company contributions, not additions to a paycheck.
For instance, State and Federal Unemployment taxes are company contributions; they are not added to or taken away from the paycheck, but the company does pay those taxes in full on the employee's behalf.
In short, you would only add healthcare as a contribution amount if the company was paying the health insurance company directly.
I'm not familiar enough with this specific situation to provide further advice, except that you'll want input from an actual accountant rather than a customer support representative. A few other users do frequent these boards, so they may weigh in with further advice later.
It'll probably need to be classed as an addition rather than a contribution in order to raise their paycheck amount; whether it should be included in their gross income or not is the real question.