Adding custom fonts to trumpet can be done via your Brand Settings.
Go to Settings and click Branding
Under Branding, choose Fonts
Click on Add Custom Font to upload and select the font/s you want to use.
Note:
You must own or have permission to upload your fonts.
Note - Only admins can upload fonts from Brand settings.
You can upload several fonts at once — select multiple font files together, enter a name for each one, and upload them in one go.