How to get full month name with DateTimeFormatter.ofPattern()

When I use this code to get the actual date:

String dateActuelle = DateTimeFormatter.ofPattern("dd MMMM uuuu").format(LocalDate.now());

It returns "06 sept. 2021" in french but I would like to get "06 septembre 2021" (full month name).

Do you know how I can do this?

While the accepted answer has correctly described the difference between MMMM and MMM, it has missed a piece of crucial information - Locale. Date-Time parsing/formatting API are Locale-sensitive and therefore, using an applicable Locale can save you from surprises and undesired results. Check Always specify a Locale with a date-time formatter for custom formats to learn more about it.

Demo:

class Main {
    private static final DateTimeFormatter FORMATTER =
            DateTimeFormatter.ofPattern("dd MMMM uuuu", Locale.FRANCE);

    public static void main(String[] args) {
        LocalDate now = LocalDate.now();
        String formatted = now.format(FORMATTER);
        System.out.println(formatted);

        LocalDate specificDate = LocalDate.of(2025, Month.SEPTEMBER, 10);
        System.out.println(specificDate.format(FORMATTER));
    }
}

Output from a sample run:

01 avril 2025
10 septembre 2025

Try it on Ideone

Learn more about the modern Date-Time API from Trail: Date Time.