For your IAM user you get a csv of credentials like this
User name,Password,Access key ID,Secret access key,Console login link
USERNAME,PASSWORD,ACCESS_KEY,SECRET_KEY,https://0123456.signin.aws.amazon.com/console
If your region is sydney (ap-southeast-2) in keepass you enter:
Title: USERNAME/COMPANY Username: USERNAME Password: PASSWORD URL: https://signin.aws.amazon.com/console?region=ap-southeast-2&iam_user=true&account=0123456
Now you can use keepass browser integration to go to that url, you will be directed to a generic sign in page, but the url matching will still work
Thank you very much!