The OER20 Conference (which was supposed to take place in London on 1st-2nd April) will be now hosted online and it is free for anyone to register.
Further details here: https://oer20.oerconf.org/news/2020/03/oer20-moves-online/
Online registrations here: https://www.alt.ac.uk/civicrm/event/info?reset=1&id=496