Got this from ESET Support. Worked for me. Might help others:
please go to ela.eset.com and enter your 20-character license key (disregarding the email address and password boxes) and click 'manage license'
at this point, an alert saying that a password reset link has been sent should appear, if it prompts for a password, please click the forgotten password link
from the email link, please set a new password for your license
please then go to eba.eset.com and once logged in, please add your license (hxxps://help.eset.com/eba/en-US/index.html?import-licenses.html) using the license key and password you created earlier in these steps