Typically, this problem arises when the product owner/vendor attempts to buy their own product. By default, the ability to purchase own products is unavailable for the product owner/vendor. We suggest trying to buy the product by logging in as a customer or visiting the product page in a browser’s incognito mode to locate the “add to cart” button on the single product page.
However, if you’d like to permit product owners/vendors to purchase their products, you can achieve this by adding a couple of code snippets to the child theme’s functions.php file. If you’re unfamiliar with managing child themes, you can use a third-party plugin called Code Snippets to add custom code to the website.
Here are the snippets you need to add, following the instructions provided:
remove_filter( 'woocommerce_is_purchasable', 'dokan_vendor_own_product_purchase_restriction', 10, 2 );
remove_filter( 'woocommerce_product_review_comment_form_args', 'dokan_vendor_product_review_restriction' );