The 30-year-old, who appeared and scored as 'Trialist D' against Sheffield United on August 2, has put pen-to-paper on a one-year deal at the Jakemans Community Stadium.
Hiwula did not play competitively in 2024-2025 - last appearing for Morecambe in the EFL in April 2024.
His most prolific spell unfolded with Coventry City between 2018 and 2020 - and he has also played for the likes of Portsmouth and Doncaster Rovers since.
Hiwula will wear squad number 16 and is registered and eligible to make his debut in the National League Cup on Tuesday evening.