Licence and source code
OfficeLabs is a fork of LibreOffice and is licensed under the Mozilla Public License 2.0 (MPL-2.0).
Source code
The modified source code is public: Pher217/libreoffice-fork on GitHub.
Licence texts
Third-party licence texts ship as LICENSE.html in the installation folder. In the application, Settings, About shows that OfficeLabs is based on LibreOffice (MPL-2.0), the source link, and where LICENSE.html is.
Trademark
OfficeLabs is an independent project and is not affiliated with or endorsed by The Document Foundation. LibreOffice is a trademark of The Document Foundation.
Website notices
The full list is on the website: Open-source notices.