IPAD 4 SOFTWARE UPDATE

I have an old Ipad4 that I want to use at work. however having dug it out of the cupboard and dusted it off, I find that it won't connect to wifi or dowload the latest ios13. The software tab tells me it is up to date but it shows my operating system as ios10.3.3. is that as high up as this Ipad goes? is that why it won't connect to wifi? (it will connect to a personal hotspot!) I'm confused, please help.