By default Ninja Forms is only accessible by an Administrator account. This is overwhelmingly the desired behavior but one some occasions you may want Ninja Forms to be able to be accessed by a lesser role within your account.
One situation where this occurs is when you are developing a site for a client and you give them only editor permissions so they don’t access things that could potentially break their site. You still want them to be able to create and manage their own forms but not give them full administrator access. Luckily that’s very easy to accomplish.