This is explicitly related to WordPress so please read this post on how to deal with this issue: https://wordpress.stackexchange.com/questions/107901/remove-the-blog-slug-from-wordpress-multisite-root-node
No, it is not possible to edit events from sub sites.
Before starting to use this addon you should have a network WordPress Multisite. please follow this external link: https://multilingualpress.org/docs/how-to-install-wordpress-multisite/ to create Multisite (WordPress Network).
Let me know if you have any other questions in the comment area.
How do i select which sit is the main site for sync.
I have 3 sites 1 main and two child, the main events calendar is on a child site but the add-on wants the main site to be the sync site.
How do i select the child site as the main.?
On the sync page, i only have listed the two-child sites and not the main site.