Typography

Download the font zip files for the necessary fonts provided above.
Unzip the file if necessary. You can do this by double-clicking the ZIP file in Finder. Open the unzipped folder. Select all the font files and double click to open Font Book to install the font.

You can select all files by clicking Cmd+A and double click any of the selected files to install all at the same time.
Click on the "Install Font" button at the bottom of the preview window. This will install the font on your Mac.

Poppins is a font designed by Indian Type Foundry. The Brahmic scripts shown here is normal.

After installing a new font, you will likely have to restart any open applications for them to recognize the new fonts.

Instruction for Windows

Download the font zip files for the necessary fonts provided above.
Unzip the file if necessary. You can do this by right-clicking the ZIP file and selecting "Extract All." Double-click the font folder to open it. Then double-click the font file to open it.

You can only install one font file at a time.
Click "Install" to install the font.

After installing a new font, you will likely have to restart any open applications for them to recognize the new fonts.