I can't begin to post all the essential noteworthy information in the ASCO. I really hope that you can try it again yourself. Log onto ASCO. Then click guest registration, signing up and then virtual live webcast. If you continue to have trouble, call the ASCO below or their website and they will guide you through the process- they actually helped me this way. Persist, because you don't want to miss it all.
webrequest@asco.org or call 703-519-2921.