DearPDF is also available as lite/free edition in Official WordPress plugin directory. You can download it from there or better install it directly from the WordPress plugin page in Adin screen. Follow the following steps in your WordPress admin to add PDF viewer and PDF flipbook plugin to your site:
Step 1: Go to your WordPress Dashboard. Navigate to wp-admin -> Plugins -> Add New.
Step 2: Then in the search box, put out this keyword ‘DearPDF’.
Step 3: In the search result, locate the DearPDF plugin, then simply click on the ‘Install Now’ button.
Step 3: After the installation is completed, click on the ‘Activate’ button and ‘DearPDF-Lite‘ will be activated.
This is how you can install and activate the free version of DearPDF-Lite.