Follow these steps to add reusable blocks to posts or pages:

1. Click the Pages menu.
2. Click the Add New button to create a page.
3. Click the Add Block button.

4. Open the Reusable section from the block to add a screen, as shown in the following screenshot:

5. Select the reusable Product Display Block you created in the previous section.
6. Click the Publish button to create the page.

Now, you can view the page on the frontend and you will see the content of the reusable block.