apache-error.log

cat apache-error-log.1                                                   [/var/log/httpd]
[Sat May 29 17:57:16.090653 2021] [php:warn] [pid 9882] [client 192.168.1.161:48092] PHP Warning:  Undefined variable $_SESSION in /usr/share/webapps/tt-rss/classes/logger/sql.php on line 13
[Sat May 29 17:57:16.090728 2021] [php:warn] [pid 9882] [client 192.168.1.161:48092] PHP Warning:  Trying to access array offset on value of type null in /usr/share/webapps/tt-rss/classes/logger/sql.php on line 13
[Sat May 29 17:57:16.107121 2021] [php:warn] [pid 9882] [client 192.168.1.161:48092] PHP Warning:  Undefined variable $_SESSION in /usr/share/webapps/tt-rss/classes/logger/sql.php on line 13
[Sat May 29 17:57:16.107164 2021] [php:warn] [pid 9882] [client 192.168.1.161:48092] PHP Warning:  Trying to access array offset on value of type null in /usr/share/webapps/tt-rss/classes/logger/sql.php on line 13
[Sat May 29 17:57:21.621407 2021] [php:warn] [pid 9882] [client 192.168.1.161:48092] PHP Warning:  Undefined variable $_SESSION in /usr/share/webapps/tt-rss/classes/logger/sql.php on line 13, referer: http://apache.twh/tt-rss/
[Sat May 29 17:57:21.621456 2021] [php:warn] [pid 9882] [client 192.168.1.161:48092] PHP Warning:  Trying to access array offset on value of type null in /usr/share/webapps/tt-rss/classes/logger/sql.php on line 13, referer: http://apache.twh/tt-rss/
[Sat May 29 17:57:21.632296 2021] [php:warn] [pid 9882] [client 192.168.1.161:48092] PHP Warning:  Undefined variable $_SESSION in /usr/share/webapps/tt-rss/classes/logger/sql.php on line 13, referer: http://apache.twh/tt-rss/
[Sat May 29 17:57:21.632335 2021] [php:warn] [pid 9882] [client 192.168.1.161:48092] PHP Warning:  Trying to access array offset on value of type null in /usr/share/webapps/tt-rss/classes/logger/sql.php on line 13, referer: http://apache.twh/tt-rss/