On Compose click Use Template (next to the counter) or Saved Templates. The Choose Template window lists your templates in collapsible cards; use the search box to filter by name. Expand a card to read the body, its character count and the "Starting at $X" estimate, then click Use Template — the text replaces the current message content and the counter updates. If you have no templates yet the window offers a + Create Template link. Note: special characters and shortkeys in the template may change the final cost.