The interface of blogger blog does not provide space to enter keywords. There is also a method described in many websites. Is it important to enter keywords in blogger blog? Because every time, keywords are added manually for all posts in template's codes.
Are you talking about META KEYWORDS? Well thats something you will be left a bit restricted of. In order to best benefit from a blogger blog you need to focus on keyword density and writing good healthy pieces of content. Top that off with Offsite SEO.