Need an add-on that can override websites that won't allow form-fill options

Hello,

I haven’t been able to find an add-on that will work with a specific website for my job… the code I think has some sort of kill function that stops from saving anything from being able to be saved. I would like an add on that can not only override this website, but also prepopulate all of the input areas on each page and any other click boxes… it’s a software system for Netsmart Devero for home health. There is ungodly amounts of computer paperwork that has to be completed all of the time and most patients have all of the same problems so I’d like for something to override it from stopping Firefox from saving the stuff and bonus points for it to prepopulate all fields. Then I could go and only edit which particular ones I need to change while leaving the other ones pre-filled out, as again, most patients have the same issues. Each start of care is 16 computer pages (would print to over 20 printed pages)… Regular visits are about 3-4 printed papers (though it pops up in one major computer form).