No workspace to create, no seats to assign, nobody to train. Your team keeps talking exactly the way they already do.
Invite her the way you would invite a colleague. She joins the LINE group and says nothing until she has something worth saying.
In whatever language your team already talks. She reads the ask and drafts the card — a draft notifies nobody, so nothing has happened yet.
She asks who is accountable and when it is checked, and how loudly to send it. Nothing reaches anyone until you say yes.
Try it with one group and one week of real work. Pricing for teams that stay is being finalised — it will be published here, plainly, before anyone is charged a cent.
Your team keeps using LINE exactly as they do today — and stops losing what they agreed in it.