Tap or click here for the full writeup on sharing from Amazon.

To add the person and grant permissions, do the following:

Go to videodirect.amazon.com. If you have an amazon.co.jp account, go to videodirect.amazon.co.jp.
On the top right of the window, click your name, and then click Your Account.
In Your Account, click Users & Roles, and then click Add User.
In the User code box, enter the user code that the other person received when they went to https://account.videocentral.amazon.com/user-code or https://account.videocentral.amazon.co.jp/user-code for amazon.co.jp accounts.
In the Email Address box, enter the person’s email address. This must be the same email address that they used used to sign in to get the user code.
Select the permission levels to grant. Note: You can only grant permissions up to the same level as your user account has.
Click Add user. To add additional people, click Add additional user.
View invite requests and statuses
To view who has accepted invite requests, do the following:

In Your Account, click Users & Roles, and then click Accepted. People who haven’t responded can be viewed by clicking Pending.
The following statuses are shown:

Invite Pending The invitation was sent, but the person hasn’t accepted (they haven’t clicked the link in the email to be added to the account).
Not Confirmed The person accepted the invite, but they haven’t completed the business profile.
Active The person accepted the invite and completed the business profile. They have access to the account based on the permissions granted.