I’m participating in an international online conference. For some reason, conference organizers thought that I must have a google calendar; therefore they provide the only button, which is a weblink for the google calendar to mark an interesting event (talk, presentation).
I’m wondering whether it is possible to redirect (local router) this kind of link to my nextcloud and add events to my calendar there?
There is mechanism available to redirect any calendar link to your Nextcloud server, but you add a Google calendar subscription (read-only mode) to your account so that all events from a Google calendar are shown in one view.
From Nextcloud 20 onwards, a new app called “Google integration” can be installed and used to access Google resources.
@j-ed but this requires to have a Google account and calendar. I thought it is possible to avoid it. On the other hand, it may be very handy to have this kind of mechanism.
Nothing is for free, if you want to rent a car and they’re only having Fiat cars but you want to drive Mercedes, there is no way to link the Fiat key to a Mercedes key so that it will open it 
BTW, you need to describe more detailed what kind of link you’re receiving, because
Oh no! I thought NextCould is free and open to the hearts of the people. 
Well this kind on links open google calendar to the event page with prefilled information. There is nothing wrong to be able to do the same in the NextCloud, right?
https://calendar.google.com/calendar/render?action=TEMPLATE&dates=20201027T150000Z/20201027T160000Z&text=%5BNMC%203%5D%20XXXXX%20XXXXXXX&details=Author%3A%20XXXXXXXX%20XXXXXXd%0A%0AAbstract%3A%20TBA
I think you can have an unlimited number of wishes but no-one will guarantee you that they will be fulfilled I think Nextcloud is always open for feature request but don’t expect that it will be implemented soon.
Well as a user, I do my best to make Nextcould better and highly appreciate the work of all developers.