If you do need an OKR that spans multiple years, create the OKR for one year and then at the end of that year continue it in the following years so the history is maintained - see How do I continue / copy OKRs to the next Quarter / Year?
If you do need an OKR that spans multiple years, create the OKR for one year and then at the end of that year continue it in the following years so the history is maintained - see How do I continue / copy OKRs to the next Quarter / Year?