Missing Snippet field in wordpress post

I’m using 5.2.5. It’s an eCommerce website named Abifoo. I’m using rankmath for the first time. Already I have rank most of the products. Really this an amazing plugin. But at the time blog post I could not find out the snippet field. We are using wp 5.2.5 version. There is a schema field available but not the snippet field under the post! But in the product section the snippet features are available(Title tag, Meta tag etc)
Please check this screenshot for the post: https://www.dropbox.com/s/1ozb271jrloxyoi/Image%201.jpg?dl=0