Henna Brows vs tint

Hello! Wondering if I could have some help regarding henna brows!

I am fully qualified in Tinting and waxing and was wondering if Brow Henna was classed as a tint and if would be ok to just order the brow henna and start offering this as a treatment. If this is the case would my insurance for tinting cover brow henna?

If this isn’t the case I’m guessing I would I need to sit a Brow henna course?

Thank you!! Really stuck on thisn