I read in this discussion (https://moodle.org/mod/forum/discuss.php?d=333441) that Moodle can log LTI requests errors, like bad json format.
Is that true? If so, how can I do this? I tried some approaches but none gave me any error messages.
I'm using Moodle 3.4, installed following this tutorial (I changed from 3.2 to 3.4): https://websiteforstudents.com/installing-moodle-ubuntu-17-04-nginx-support/
I attached the config files from my nginx, php-fpm and moodle.