Captive Portal & input form on mobile

[thekingshorses]

I have a captive portal set up with a simple password "password"

On mobile devices, by default first character is uppercase. So when the user types in, it types "Password", and the user can't log in. They get frustrated and call support.  

Is there a way I can modify the HTML login page? If I can modify the HTML page, I can change the input form to lower case by default. 

Or is there a way to have two passwords for guest access - "password" & "Password"?

Or is there a way to ignore the case?

[thekingshorses]

Changing the <input> to 

<input autocapitalize=off>

will fix the issue. But I am not sure how to access/modify the HTML page.