am totally confused about this matter. My hosting provider doesn't allow SSL certificate. I want to know, is SSL certificate important fact for SEO? Now, what can I do?

Yes SSL certificates are good for search engine optimization. Google prefers them.

it does not affect you SEO

SSL does affect SEO but it is only one of hundred factors that Google consider to rank a website in search engine result page. Having an SSL can be an advantage for you.

yes, SLL certificate help in fast indexing, But you have to also complete on-page SEO to increase its visibility.

Yes, it's true that SSL certificate affects SEO because user will only browse and visit the trusted and secure websites which ranked in search engines.