You can customize the product page by heading towards:
Dashboard >> Appearance >> Customize >> Reign Dokan >> Product Page
Show Vendor Header – This allows you to show the vendor header on top of the product page.
Show Vendor’s Products Section – This allows you to show vendors’ products on the product page.
Number Of Products – This allows you to select a number of products to show in the vendor’s products section.
Show “Sold By” Info – This allows you to show “Sold By” information in the product meta information section on the product page.