I try to generate a PDF using html2pdf but it wont work?

Looking at the code we fount that you are using a CSS attribute to avoid the section of been broken on many pages. 
The issue here is that in this section if the content is taller than a letter page it will crash in the generation by not been able to keep the content together. 

We remove this style="page-break-inside: avoid;" CSS and then the generation work perfectly.

Avoid using the below attribute if you it is on a section where the height is variable based on the content : 

style="page-break-inside: avoid;"