You’ll need to be able to build a Conga Composer button. You can find the details on how to do this in Conga Composer QuickStart 1 – Creating Your First Conga Composer Solution.

Due to the potentially complicated nature of HTML source code, our support staff can only assist with the creation of Conga Email Templates edited using the non-Source view mode in the Conga Advanced Editor. Editing the template through the Source view in the Conga Advanced Editor constitutes an unsupportable, "use-at-your-own-risk" configuration.

Conga highly recommends excluding the "Use attachment for template body" checkbox field from the Conga Email Template page layout. Use of this field is only suggested if your Conga Email Template is more than 32,000 characters, in which case the body of the Conga Email Template can be added as an attachment to the Conga Email Template record.