I've been using Rotativa[1] for URL to PDF generation which is also a wrapper for wkhtmltopdf. They have a dotnet-core[2] version and also a SaaS[3] but it's worth mentioning that Azure PaaS supports wkhtmltopdf[4] so I just self-host.
Looking at QuestPDF's API docs, it doesn't look like they support URL / HTML to PDF generation. I think this would be a great addition especially given the age and issues with Rotativa and TuesPechkin on their public repos.