In order to export your template, first you will have to obtain its code. Templates created both in the Drag & Drop editor and the rawHTML editor keep their code ready for export.

Regardless of how the template has been created, any of them can be opened in the rawHTML editor. Just click on the three-dot menu besides a template of your choosing and pick "Edit as HTML":

On the resulting screen you will be presented with the entire HTML code of your template. Besides making necessary tweaks if you are proficient in coding, you can also copy this code and take it outside of the editor.

Please note that if a template was created with the Drag & Drop template editor and then its code copied and pasted elsewhere - it will lose its editor properties and will be editable only via the HTML editor.