All very confusing, Q1 or Q2

Hi,
I am a UK man that married a Chinese lady in 2003. I stayed with her until January, 2018 when I returned to the UK to buy a house for our retirement. My Chinese wife is still in the mainland of China(PRC), but I need to return to help her with her immigration application to come live in the UK.
Do I need to apply for a Q1 or Q2?
There does not seem to be a clear definition, unless I am reading it wrong!

I look forward to your reply.

Paul