Lota Local self-hosts Source Serif 4 and Source Sans 3 through Fontsource packages.

Source Serif 4
Copyright 2014-2021 Adobe (http://www.adobe.com/), with Reserved Font Name 'Source'.
Licence: SIL Open Font License 1.1
Package: https://fontsource.org/fonts/source-serif-4

Source Sans 3
Copyright 2010-2021 Adobe (http://www.adobe.com/), with Reserved Font Name 'Source'.
Licence: SIL Open Font License 1.1
Package: https://fontsource.org/fonts/source-sans-3

The full licence text is included in each pinned Fontsource package distribution.