Problem entering data

[wbw]

Hello all. Been using Fuelly for a few years but now have a question. I now have three vehicles entered for tracking. For the first two vehicles I can enter 'Miles since last fill up'. For the third vehicle which I have just added, I am not offered that box. Instead the screen asks for 'odometer reading'. I prefer the miles since last fill up. How can I get that option for my miles instead of odometer reading?

BTW, I am entering data from my computer, not an App.

Thanks for any help.