how to target similar keyword in post

If you have done proper keyword research by following the complete procedures, then you should have also done keyword mapping and grouping. In this you put all the related or similar keywords in one group and for that specific group, you create a blog post. As xcode919 has mentioned, You should be using more LSI keywords and longtail forms of your primary keyword in a 1000 words descriptive article. Dont just focus on putting keywords randomly or trying to force keyword placements in your article. Just focus on providing quality to the user or Reader of your article . Just by keeping your article related to your primary as well as many secondary or longtail keywords (of similar Intent), You will rank for multiple variations of your primary keyword. Because google knows the intent of your article and will show your content to the users searching for it. I have seen in many cases that certain blog posts were ranking on top for the keywords that the author did not even used as exact match in their article. Just because the intent of article was same and it was providing quality, it got ranked on top. Hope you get the basic idea.