Sleek huge chapter header?

I have been trying to customise the titles of my chapter as being flushed to the right, with the chapter number in size 96pt, above the chapter name (huge), specifically like this TU Delft template my code is inspired from:

I am using LateX in Overleaf. The layout is working fine, however, I am having a problem with the font setting (I am rather new to LaTeX…) as for whatever reason, the chapter number appears bold while I haven’t put any bfseries or anything similar anywhere, so my fontseries{l} seems to not be working fine. Also, when I tried to import some font packages (like roboto) with the attribute [thin] like so: RequirePackage[thin]{roboto}, the quotes in italics in my main text .tex files switched back to normal while textit{} was still there (???).
Problems aside, could you please tell me how to improve my code and which font I should use to sort of match the number in the exemple picture above? (and how to use this font, since I’m rather new…!) Thanks!
Note: the code below was written in a .cls file which is then imported in my main .tex.

NeedsTeXFormat{LaTeX2e}
LoadClass{report}
RequirePackage[noindentafter]{titlesec}
renewcommand{familydefault}{sfdefault}

titleformat{chapter}[display]  
    {flushrightfontfamily{qhv}fontseries{l}fontshape{n}}
    {fontsize{96}{96}selectfontthechapter}
    {0pt}
    {sffamilyfontshape{n}Huge}
    {}