you can start with the free version yes, later on, when you grow you can get the premium

@admin
Thanks for the reply, sir, But need clarification on one more thing,
One of the main features of the premium version is the option to add additional keywords. So don't we have to follow the same steps as the first keyword for the second one? But when it comes to the URL, how can we add one more keyword? Won't it increase the length of the URL and affect the SEO? or do we have to compromise on those?
Just for an idea, How many keywords do you use on average on your blog articles?

no friend, the URL will focus only on the main keyword, the other keywords are related that you can also use to rank. like some other long-tail keywords or LSI keywords and so on. focus on the main target