Add multiple tags on ticket creation when using the API

What’s the syntax to add multiple tags to a ticket? I’m working in powershell and my script works as expected, I’m just not able to add multiple tags.

These don’t work:

$body.Add('tags','Onboard/Offboard',’onboarding’)

$body.Add('tags',['Onboard/Offboard',’onboarding’])

$body.Add('tags','["Onboard/Offboard","onboarding"]')

Not sure how to do this.