This assumes that you have FAQs already created and they belong to certain category.
In this example, we will add these FAQs to specific product.
If you are using Online Store 2.0 compatible theme & If you wish to show specific FAQs on specific product then follow this tutorial

1. Once you are done adding FAQs, go to "Categories" section in app and copy a code of category you would like to show on a product.

2. Go to your Shopify Admin > Products > All Products > Select a product where you would like to add FAQs.

If you would like to show only on certain category products then you can go to Products > Collections > Click on product.

3. Click on "Edit HTML" button from text area and paste code you copied at step #1.

4. Save page and you should see FAQs that belonging to that category on your product page.

5. If you still don't see FAQs on your product page, make sure you have enabled a feature through settings. Please follow these steps to make sure feature is activated.

Design and Settings > General > Show FAQs on other pages > View Settings > Activation > Activate.

After activation, you should start seeing FAQs at appropriate place.