My answer might be biased, since I have an engineering background and code almost daily.
I think it's important for a founder to know how to code, but not required. There are plenty of people who can't code who have started successful SaaS companies.
Having a technical co-founder would significantly improve your odds of success. At a minimum, you should have an advisor who can guide you through some of the technical aspects.
If you have some coding skills, that'll do. You don't need to be the best engineer. You'll find that most successful founders are generalists, not specialists.
I'm one of those that @Nishank mentions - I cannot write code, but I am a founder of a B2B SaaS company. My lack of ability to code has been a definite help.
It helps my customer(s) because I speak their language, not technical speak.
It helps the tech people, because I don't attempt to define the technical solution, I describe what the customer/user needs.
It helps my company build a value proposition and sell it, because I understand how our clients business works, and how the various levels/functions of people in those businesses are motivated.
I could talk about this for hours - but it comes down to "it depends", on many things.