How long before can one fill the ILR SET (O) application form?

[heyitsme]

My initial T2 Visa issue date is 28th August 2016. As one can apply 28 days before the T2 visa issue date so i can apply on 1st August 2021. I have filled the online application form but I am not sure if this is a right thing to do. Which of the following is more suitable for my circumstances?
1) can I pay for the ILR fee now and just get the biometrics date after 1st August 2021
2) Should I save the application and pay for it on 1st August and then book biometrics
3) Should I discard the application and make a new online application on 1st August 2021?

[zimba]

Apply now and book the appointment for 1st August. It is fine

[heyitsme]

Thanks
I am a bit confused as I was told that if I pay now then my application would be considered as starting from the date of payment and it doesn't matter if i get the appointment after 1st August. Thats why I am confused.

Has anyone done like this before?

[heyitsme]

https://www.freemovement.org.uk/applica ... in-the-uk/

This link mentions that for online applications the date application is submitted online is the date of application

[zimba]

indefinite-leave-to-remain/dependent-il ... l#p2020249