How to Change the Appearance of the Fonts in Blocks
Blocks include the fonts tab ('T' icon).
The options displayed in this tab will depend on the block type. Each block type is slightly different and will only display the options that apply to the block.
The four options are:
Main Heading
Main Subheading
Elements Heading
Elements Subheading
By default, the font styles are set to the system defaults.

Please Note: If you aren't seeing the option in your blocks, you will need to start by updating the Legacy Font options within Font settings, click here to view more details.