LET'S DO THIS!
Here are the 7 steps for adding me to your account with Editor Access
STEP 1: Log into your KDP account: kdp.amazon.com
STEP 2: Click on Promote & Advertise for your book on the bottom right.
STEP 3: On the bottom right of the screen select Amazon.com as the marketplace and select create ad campaign.
STEP 4: Hover over the 3 lines on the top left next to amazon advertising
STEP 5: Click on account access.
STEP 6: Click on invite user and use the below credentials:
IMPORTANT: EMAIL IS CASE SENSITIVE!
STEP 7: Hover over the left dark blue bar again and select billing and payments this time. Click on payment settings and add your payment information. I don't have access to this tab.