First, it is important that all participants in your planned event series have the same participant code. This is important so that the codes are correctly transferred in the invitation e-mail.
In other words, if participant A should have the opportunity to participate in Event A and Event B, participant A must have the same participant code in both events. Then the code will be correctly adopted at the registration.
Export the participant list including the participant codes from one event and import them into the other events of your series.
In the second step, open the event website of each event and copy the URL of the registration page from the browser line. Please note that the events must be activated for this. Then add the placeholder ?code=%participantCode% to the respective URLs.
Please find an example below:
The original URL is https://eveni.to/testevent/anmeldung.
If you now add the placeholder ?code=%participantCode%, you will get the following URL https://eveni.to/testevent/anmeldung?code=%participantCode%. The personalized registration link is created.