The merge tag button is in the editor toolbar on the Email Template Workspace. Here is how to find it:

1. Go to Communication > Email Templates from the main menu.
2. Open any email template.
3. Click the Design tab to open the Email Template Workspace.
4. In the editor toolbar, look for the tags icon with a Tags label. Its tooltip reads Insert Merge Tag.
5. Click it to open the merge tag picker.

Good to know: the merge tag button only appears in the Email Template Workspace editor. It does not show up in other editors around Argenta (notes, descriptions, content editors), because merge tags are specifically for email personalization.

If you do not see it: make sure you are on the Design tab (the Email Template Workspace), not the Template Details tab. The Details tab manages settings like the campaign, organizational hierarchy, and record permissions; the editor with the merge tag button is on the Design tab.