I cant access my store after installating OpenCart 4.0.1.1

I updated my opecart to version 4.0.1.1 and PHP to 8.1. The update was successful, but i cant enter my page. I get the following error when trying to access the webstore: Parse error: syntax error, unexpected token "/", expecting ")" in /www/webvol16/tv/2gs0h2ugbpsgsgu/swedgate.com/public_html/admin/config.php on line 16
What should I do?
Thanks

Do you have a full backup of the database and files of your old version to restore from?

Or post here the whole content of the admin/config.php >> WITHOUT sensitive data (DB-password for example) !