You need to add the below lines in .htaccess file if you want your PHP errors within the error_log file instead of the .logs folder.
IMP : Ensure that you take the backup of your existing .htaccess file before making any changes. Incorrect .htaccess may cause the issue to your website and it may become inaccessible.
# log PHP errors to a file
php_flag log_errors on
php_value error_reporting 32767
php_value error_log "error_log.txt"