Go to https://account.cern.ch/account/ and create a lightweight account, then sign in.
At the bottom of the front page, find the "Submit new abstract".
Please follow the instruction to fill in the form, select options and attach abstract files.
About the contribution type, choose which you prefer the most. After consulting you later on, the WCPE organizers might change the type: whether you present in person or online, in which time zone you present and in which category your contribution falls.
About the authors, clarify the corresponding author, co-authors and indicate who will be the presenter.
About tracks, it is possible to select several topics which are later on merged into fewer thematic groups.
Please do NOT FORGET attach your abstract proposal using the template which can be downloaded here.
The WCPE organizing committee