When should I apply for student finance if I'm taking a gap year

I've already received offers from the Unis I want to attend, and I've applied saying I am deferring my entry.
When should I apply for student finance, I've searched everywhere but found nothing.
A teacher from my school thinks there's an option to defer the loans coming in till 2024 when I start my uni term but I am unsure.
Hope to get a response asap