When should we apply for FLR?

Hello, I was wondering when I should apply for FLR. I want to hopefully be able to get the 5 year ILR (I know this might change but want to be prepared)

Dates are below

Visa was granted from 18 June 2024 to expire on 18 March 2027.

I entered the UK on 3 July 2024.

Any guidance would be greatly appreciated because I have seen 28 days before expiry mentioned and also three months before expiry mentioned. It’s rather confusing.

Thank you