Many people think they cannot apply for a visa without getting an invitation letter. This is not correct. It is better not to get an invitation letter from anyone and travel as a tourist.
When you get an invitation letter from someone, it makes the application more complex. The person inviting you may have an adverse immigration history and importantly they will need to provide their documents as well.
Of course, there are some minor situations where getting an invitation letter will be advantageous. But it is in the few? We advise you to get an invitation letter from a well-known or a close family member.
So answering the question – do you need an invitation letter for your visa application, the answer is No