As a broker, your permission to join the supplier group(s) you represent needs to be validated by a SRM.
It may be faster to notify each supplier by contacting that respective group's admin for this portal. Request to have them add you to their group and change your privileges accordingly.
Please email this link onto your supplier(s) on how to add you to their group:
If you don't already have a Supplier Portal account:
Create a New User Account (as a broker) and please include your Portal username when requesting access from your supplier group's admin.