Endpoint documentation is available at https://bungie-net.github.io/multi/
You will need an API key from https://www.bungie.net/en/Application and some endpoints require access tokens (available by logging in through Bungie oAuth - see https://lowlidev.com.au/destiny/authentication-2 for authentiation flow examples)
$api = new \AdamDBurton\Destiny2ApiClient\Api('{api-key}');
Implementation - https://github.com/adamdburton/destiny-2-api-client/blob/master/src/Api/Module/App.php
Accessed through - $api->app()
Implementation - https://github.com/adamdburton/destiny-2-api-client/blob/master/src/Api/Module/Destiny2.php
Accessed through - $api->destiny2()
Implementation - https://github.com/adamdburton/destiny-2-api-client/blob/master/src/Api/Module/User.php
Accessed through - $api->user()
Not yet implemented
Not yet implemented
Not yet implemented
Not yet implemented
Some endpoints require an oAuth token with applicable scope permissions.
$api->user()->withAccessToken('{oauth-token}')->getMembershipDataForCurrentUser();