addLegalSection  
  fun addLegalSection(title: String, copyright: String? = null, licenseType: <Error class: unknown class>, license: String? = null)(source)
Adds an extra section to the Legal page.
Extra sections will be displayed below the application's own information.
The parameters @copyright, @license_type and @license will be used to present the it the same way as property@AboutWindow:copyright, property@AboutWindow:license-type and property@AboutWindow:license are for the application's own information.
See those properties for more details.
This can be useful to attribute the application dependencies or data.
Examples:
adw_about_window_add_legal_section (ADW_ABOUT_WINDOW (about),
                                    _("Copyright and a known license"),
                                    "© 2022 Example",
                                    GTK_LICENSE_LGPL_2_1,
                                    NULL);
adw_about_window_add_legal_section (ADW_ABOUT_WINDOW (about),
                                    _("Copyright and custom license"),
                                    "© 2022 Example",
                                    GTK_LICENSE_CUSTOM,
                                    "Custom license text");
adw_about_window_add_legal_section (ADW_ABOUT_WINDOW (about),
                                    _("Copyright only"),
                                    "© 2022 Example",
                                    GTK_LICENSE_UNKNOWN,
                                    NULL);
adw_about_window_add_legal_section (ADW_ABOUT_WINDOW (about),
                                    _("Custom license only"),
                                    NULL,
                                    GTK_LICENSE_CUSTOM,
                                    "Something completely custom here.");Content copied to clipboard
Since
1.2
Parameters
title
the name of the section
copyright
a copyright string
licenseType 
the type of license
license
custom license information