You can follow these steps to add Facebook Post to Google Sites.
#Option 1. Add single Facebook Post to Google Sites
#1 . Click 3 dots on the right of a Facebook Post > Click Embed
#2 . Next, click Copy Code
#3 . You can add it to Google Sites via Embed feature.
#4 . Paste your Facebook Post to embed code box
#5 . Result
#Option 2. Add Multiple Facebook Posts to Google Sites
To add multiple Facebook Posts to Google Sites, you can use this free tool. Follow these steps.
#1. First, access this free tool and click Create widget for free
#2. Choose Facebook Posts layout and click Continue with this template .
#3. Next, After connecting to your Facebook Account
You can also set layout, style here then click Add to website for free.
#4. Next, Click Publish on top right
#5. Choose Free Plan and click Copy Code .
#6. You can add it to Google Sites via Embed Feature.
#7. Paste your embed code
#8. Click Insert
#9. Result