There is a requirement to generate a PDF and upload into a document library from dynamic HTML content created using Nintex workflow in SP online.
How can this be achieved?
To the best of my knowledge neither Nintex, nor SharePoint Online provide functionality to do this natively, so you have to use 3rd party functionality or write a helluva lot of code.
I wrote a couple of blog posts on this subject recently as Converting HTML in SP Online is a hot topic because it makes content generation very easy.
Have a look at the following:
There is a couple of things to take into account. Nintex for Office 365 currently does not support direct integration with third party software like their on-premise products do. Therefore you have to use the workaround in the 2nd blog post linked to above to invoke a REST API. It is all a bit messy, another option may be to create a SharePoint Designer workflow (which does support 3rd party components) and invoke that workflow from Nintex Workflow.
The other thing to take into account is that I wrote those blog posts and worked on the product mentioned, so consider me biased (but very knowledgeable on the topic).