When you add your classes make sure to customize the filter inside each page's coursework masterlist. This allows you to see only the due dates for the specific class.
To add additional classes click add and select the add a class template.
I used indify.co to add the buttons. Sign up for an account, customize to your liking and then paste the code at the bottom into your notion and click ‘embed’
note - use $$ before and after code
$\color{#ced2af}hello\ friends$
\color{#ced2af}hello\ friends
Custom Text Box
$\colorbox{#919f89}{hello friends}$
\colorbox{#919f89}{hello friends}
Combination
$\color{ffffff}\colorbox{919f89}{hello friends}$
\color{ffffff}\colorbox{919f89}{hello friends}