What happen if I don't have custom 404 page on the backend of the website?
So, I have in the issue I don't have a 404 page on the backend of the website, and it automatically redirects to the homepage, so do I need to use a redirect, or not in that case?
Redirecting to the home page is not ideal. They were trying to find a specific article and unless they are a loyal fan you will most likely lose them. Don't spend to much time on your 404. The main objective is to not have anyone reach that page because your links are working or 301 to where you want them to end up.
I would simply add a custom message and search bar helping them find the type of content they are looking for to start. You can always go back later and customize it further.
Do Set it up,
the default would be a server-generated 'Not Found', looks shabby
just get it done.