Upgrading WooCommerce Email Template Customizer from Free version to Premium

Hello,
I recently purchased the premium version of “WooCommerce Email Template Customizer” and when I installed premium version, the customized templates I had created in the free version did not transfer over to the premium version.
Can you please let me know what I have to do to ensure my pre-existing customized templates from the free version will transfer over to the premium version when I install the premium upgrade?
Thankyou