An Indico account is mandatory in order to submit an abstract (or any material) in Indico.
If the institution/experiment/university is registered with Edugain, users can use their email address directly in order to login.
Otherwise, they have to create an external account (using their institutional emails) by clicking here.
After having created an account, the users will receive an email with easy instructions to follow on how to confirm account creation. After that, they will be able to upload their own abstracts.