Sign up here- https://www.powr.io/plugins/ecommerce (POWR e-commerce comes with basic free plan, you can upgrade if required. )
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 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.
Make sure to click on Publish or Update live site button after making the changes to save and publish new changes.