Parent-Child has no relationship in Moodle

Hi,
I have Joomla integrated with Moodle via Joomdle and Hikashop on my website.
Also I have enabled the Joomdle menu items children registration and assign courses.
As a parent in the Joomla frontend I create a child and I assign it the course I have bought.But although the child is
enrolled in this course in Moodle, there is no parent-child relationship in Moodle which is what I want to have.
Do you have any ideas how I can fix this or generally how I can achieve this parent-child integration?
also i would like to know where joomlde stores the "joomla server url" so we can change it from command line. the field is in moodle at site administrator ->plugins->authentication-> joomlde.

thx a lot for your time

Did you configure the parent role in Moodle, and set its ID in Joomdle config in Moodle?

I setted the ID in Joomdle config in Moodle but now on the frontend of my site when I log in as parent and I buy a course or I register a child and then I go to the assign courses menu item, the my courses field and available children field are empty. Moreover, do you have any idea that would help me with the server question I asked you above?
Thanks in advance.

I fixed it eventually I had disabled the buy courses for children option because I had a problem before and now I enabled it and it works. But I still don't know where joomlde stores the "joomla server url" can you help me with this? Thanks a lot for your time.