Apply for settlement

[regcheck]

Hello

I'm currently on my Tier 2 PBS dependent visa and I'm eligible for ILR under 5 year route by December 2020.
Currently My partner is UK citizen from 2018 ( based on tier-2 , 5 year route).

So I have to apply for settlement based on which application form SET(O) or SET(M) please could you advice ?

Thanks in advance

[srsw]

Set (O)