How to select a post as the Courses? Where could I find the Post ID?

Hi, I want update the Course section, showing our customized contents. As the tutorial, I have 4 options: Post, Page, Category, Image. In terms of Post, the tutorial is as follows: How to enable Post Content?# Make sure Events is enabled Under “Select Content Type”, you need to select “Post” Then, add in Post ID in Featured Post 1, Featured Post 2 and so on Finally, click on “Save & Publish” I just do not know how to find the Post ID of a specific Post. Please help me. Thanks. Jeremy