[Bug] ApiPage.html.primary.js from the modern template doesn't seem to be used

[KubaZ2]

I am trying to add canonical link to my website that is generated by docfx. It should be easy with _path defined by docfx, but I would like the canonical link to be for example https://example.com/ instead of https://example.com/index.html, because my server is configured to redirect ./index.html to ./. I noticed that ApiPage.html.primary.js as well as other similar files I have created are never used when building using docfx with this template.

To Reproduce

1. Clone https://github.com/NetCordDev/NetCord
2. Edit https://github.com/NetCordDev/NetCord/blob/alpha/Documentation/templates-src/NetCord/ApiPage.html.primary.js
3. Notice the file doesn't change anything

I use docfx 2.75.3 but 2.77.0 doesn't seem to fix this. The template's source comes from docfx 2.75.3.