channelName check failed, should be a non-empty string<br />
<b>Fatal error</b>:  Uncaught Error: Call to a member function addPrivilege() on null in /home/customer/www/v.webdidas.com/public_html/yonsei_app.php:19
Stack trace:
#0 /home/customer/www/v.webdidas.com/public_html/yonsei_app.php(13): RtcTokenBuilder::buildTokenWithUserAccount('01cc9e0980c449b...', '349870e228dc423...', '', NULL, NULL, 1623663892)
#1 /home/customer/www/v.webdidas.com/public_html/yonsei_app.php(43): RtcTokenBuilder::buildTokenWithUid('01cc9e0980c449b...', '349870e228dc423...', '', NULL, NULL, 1623663892)
#2 /home/customer/www/v.webdidas.com/public_html/yonsei.php(5): require_once('/home/customer/...')
#3 {main}
  thrown in <b>/home/customer/www/v.webdidas.com/public_html/yonsei_app.php</b> on line <b>19</b><br />