To send a template, make sure you are in the right Association (i.e. the same record type as specified as the Association on the template). This example is within a Lead record.
Click on the Touchbar>Send a Template.
Choose the Template Folder to which you saved your template.
Your template will be shown in the Template list. If it does not appear, then you have not chosen the correct Association for the Template (or you are not in the correct Record Type). This is a Lead template so the Association is Lead.
Once you have selected your chosen template, click Preview.
Any workflow or follow up set for this template will be displayed as will any documents automatically attached.
Your personalised template will be displayed with all tags populated.
Once you are ready to send the template, click Send a Template.