Forticare license for a new FortiAP 231g

[rouzbeha]

I have a fortiap 231g, which I purchased new and it is still on the 3 months Fremium license that comes with the device. now I want to extend the license to keep receiving firmware updates. I don't need other support options in Premium and Elite licenses. With this can I buy a Forticare Essential license or I have to buy Premium/Elite for the first year and then extend by Essential license later? I receive conflicting info from different sources, including my official Fortinet rep who says I must buy Fortinet Premium for the first year, then extend with Essential from the second year. 

Any idea what the truth is?