cause = foreach() argument must be of type array|object, null given

Hi
im getting issues with projeqtor

first of all, i got this message in log file:

on file '/var/www/sipro.emaransac.com/view/refreshLastNews.php' at line (66)
cause = Undefined variable $json 
then i put in that php file this line
global $json;

now i got another error
cause = foreach() argument must be of type array|object, null given

i dont know why im getting those errors after a fresh install, i didnt do any change in files before

im using php 8 with mysql and apache
how can i solve it?