html2canvas in Angular - Cannot invoke an expression whose type lacks a call signature

Solved! Thank you :)

Finally I imported in that way:

import html2canvas from 'html2canvas';

For Angular 8, see this link: https://github.com/niklasvh/html2canvas/issues/1896#issuecomment-506129710

Basically, you need to have version 1.0.0-rc.1 of html2canvas installed for it to work.