Edit file File name : AccessTokenEntity.php Content :<?php namespace Api\V8\OAuth2\Entity; use League\OAuth2\Server\Entities\AccessTokenEntityInterface; use League\OAuth2\Server\Entities\Traits\AccessTokenTrait; use League\OAuth2\Server\Entities\Traits\EntityTrait; use League\OAuth2\Server\Entities\Traits\TokenEntityTrait; class AccessTokenEntity implements AccessTokenEntityInterface { use AccessTokenTrait, TokenEntityTrait, EntityTrait; } Save