Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
Hello Eanson_chen,
Thanks for your post in Microsoft community. Regarding your issue, we would like to suggest you to use open network , use different browser or use InPrivate mode and check if it helps to register for Office 365 Trial version.
If it’s not help and if you are sign up for Office 365 first time, we would like to suggest you to check with Sign up for an Office 365 trial subscription.
Thanks and regards,
Ankita Vaidya