PHP-File中的身份验证请求解码无法提供正确的值

I'm setting up a SSO login for dokuWiki. My oauth plugin for dokuWiki needs to authenticate against an ESI server of the SciFi-MMO Eve Online (CCP).

The current state is, that i can log in at the Eve authentication website, but my Wiki throws the "EVEOnline did not provide the needed user info. Can't log you in" error (to find at the bottom of the second code block) and stops the login process.

I'm using a vServer, Ubuntu 16.04, dokuWiki (latest), oAuth Plugin (latest), a NGINX webserver and PHP 7.3

When putting in some print and var_dump lines, i'm getting the following results:

var_dump($result) = array(6) { ["CharacterID"]=> int(00000000) ["CharacterName"]=> string(4) "TEST" ["ExpiresOn"]=> string(19) "2019-04-04T21:10:46" ["TokenType"]=> string(9) "Character" ["CharacterOwnerHash"]=> string(28) "xxxxxxxxxxxxxxxxxxxxxxxxxxxx" ["IntellectualProperty"]=> string(3) "EVE" }

var_dump($username); = string(4) "TEST"
print ($username); = TEST

var_dump($uinfo); = bool(false)
print ($uinfo); = Array

class EVEOnlineAdapter extends AbstractAdapter {
    /**
     * Retrieve the user's data
     *
     * The array needs to contain at least 'user', 'mail', 'name' and optional 'grps'
     *
     * @return array
     */
    public function getUser() {
        $JSON = new \JSON(JSON_LOOSE_TYPE);
        $data = array();
        $json = $this->oAuth->request('https://esi.evetech.net/verify/?datasource=tranquility');
        $result = $JSON->decode($json);
        $json2 = $this->oAuth->request('https://esi.evetech.net/dev/characters/'.$result['CharacterID'].'/');
        $result2 = $JSON->decode($json2);
        $username = str_replace(array("","'"),"_", $result['CharacterName']);
        $data['user'] = $username;
        $data['name'] = $result['CharacterName'];
        $data['mail'] = $username."@eveonline.com";
        if($result2['99008040'] !== '99008040') {
                return false;
        }
        return $data;
    }

    protected function processLogin($sticky, $service, $servicename, $page, $params = array()) {
        $uinfo = $service->getUser();
        $ok = $this->processUser($uinfo, $servicename);
        if(!$ok) {
            return false;
        }
        $this->setUserSession($uinfo, $servicename);
        $this->setUserCookie($uinfo['user'], $sticky, $servicename);
        if(isset($page)) {
            if(!empty($params['id'])) unset($params['id']);
            send_redirect(wl($page, $params, false, '&'));
        }
        return true;
    }



    protected function processUser($uinfo, $servicename) {
        $uinfo['user'] = $this->cleanUser((string) $uinfo['user']);
        if(!$uinfo['name']) $uinfo['name'] = $uinfo['user'];

        if(!$uinfo['user'] || !$uinfo['mail']) {
            msg("$servicename did not provide the needed user info. Can't log you in", -1);
            return false;
        }

I expect a normal login flow with access to the Wiki after authenticating through Eve Online.

To me it looks like that the $uinfo variable needs to contain TEST as the correct 'user' instead of "Array", but i don't know why getUser() doesn't provide the correct data.

Can anyone help me with this problem?

Thanks in advance