The BMW X1 has a petrol engine and the BMW iX1 is the electric version of it. I expect and hope the BMW X1 will join the scheme next year. However the electric iX1 starts at £52,390 so it seems unlikely that it will.
As I said a few posts back, BMW has announced a lower powered iX1 which will retail at around £7k less, so that is likely to appear I’d suggest. As 72 dudes says, there is no logic to which cars appear and which cars don’t, when it comes to retail price and AP, especially when it comes to EVs.