how do i make the boxes checked?


Replace the<i class="________"></i> tag beside each item, they will all mostly have the empty box by default which is  <i class="fas fa-square text-muted my-auto"></i>

Replace them with whichever one applies. These are using premade icons that are implemented in the site's code.
These codes will change the icons to be whatever one you need them to be. And I also tried to explain a little bit about how they work.


<i class="fas fa-square text-muted my-auto"></i>

Empty 
"Square" makes it an empty checkbox. "muted" makes the color muted based on the theme you're using.  (color varies depending on theme)


<i class="fas fa-check-square text-success my-auto"></i> 

Yes  (Checkbox) 
"check-square" makes a square checkbox. "Success" makes the font green (color varies depending on theme)


<i class="fas fa-times-square text-danger my-auto"></i>

No  (X) 
"times" adds X. "square" indicates it'll be in a square. "danger" makes the color red. (color varies depending on theme)


<i class="fas fa-question-circle my-auto"></i>

Maybe / Unsure  (?) 
"question" makes a question mark "circle" indicates it'll be in a circle (probably also comes in square flavor like this fa-question-square)
Leaving out any color indiating tag will let it do the default text color for TH themes


<i class="fas fa-comments text-danger my-auto"></i>

Discussion Required (Chat bubble) 
"comments" makes the icon a chat bubble. "danger" makes the color red