There are two steps.
The first step is to add the ID “anchorlinkname” to your blog post. Do this by embedding the code in a similar way to the below code - embedding code is not the same as adding a link. In your screenshot you are adding a link but you should click the embed code option instead.
The second step is to add the “#anchorlinkname” to your menu so that when you click on your menu it goes to the ID “anchorlinkname” in the blog post.
Please follow the instructions for step two in the video I originally sent you. For step two just create a regular link that looks something like this.
This will create a link from the menu to the ID you created in step 1.
The #anchorlinkname in your menu and the ID “anchorlinkname” in your blog post need to have the same name.
Remember to publish before you test to see if it is working because it will not work in preview mode.
A very basic understanding of the way regular anchor links are created may be helpful.