After signing up, click on Add Ecommerce to Site button
In next step, choose HTML from the available options
Fill the required details like Payment options, product images and details, price etc.
After adding the products and configuring required setting generate the embed codes. (see the image below)
Click on Add to Site button to generate the Embed codes
Open the VINTCER editor and choose RAW widget (last option) from section menu
A empty RAW widget will be added to your website
Click on RAW ELEMENT and then click on Edit Widget button
Paste the POWR code in to code editor and click on SAVE button. Thats it, POWR e-commerce plugin should be added to your website.