Step 1. In the download module folder, you can find the "fonts'' folder. upload this folder files with your WHMCS (whmcsroot/assets/fonts/).
Step 2. Login as whmcs admin.
Step 3. Go to "Setup" >> "General Settings" >> "Invoices" >> find the "PDF Font Family" >> choose "Custom" type >> enter the font family name "dejavusans".
Note: Only upload the fonts folder files. don't replace the folder with the existing one.
