I would like to add a HTML block on every single product between “buy now” and “Tabs” as shown in attached screen shot. I found I can add it after buy now button, but it’s only shown right half of the page. And I don’t want to add it as a Tab. Or I have to add this block for each product and it’s a lot of work. Is there any way to add the block in a proper way on every single product page?
You need to create an HTML block for every single product, then select this HTML in the extra content and set the location in the bottom of the product settings. https://ibb.co/pzrg9f8
Try to use the Theme’s Layout Builder you can create Custom Layouts for WooCommerce pages like Shop, Category, Single Product page, Cart, and Checkouts. You can use that to create your own custom layouts for single product page.