AWS Lambda and Custom webhook stage does not work

I set up a lambda stage with reference to this guide.(https://kb.armory.io/aws/AWS-Lambda-HowTo)
It works fine if I don’t set account permissions.
here is my config…
<clouddriver-local.yml>

.....

aws:
  lambda:
    enabled: true
  accounts:
  - name: prod-aws
    lambdaEnabled: true
    environment: prod
    requiredGroupMembership: []
    providerVersion: V1
    accountId: 'XXXXXXXXXX'
    regions:
    - name: ap-northeast-1
    assumeRole: role/spin-managed-test
.....

But, if I set account permissions, I get an access denied error.

.....

aws:
  lambda:
    enabled: true
  accounts:
  - name: prod-aws
    lambdaEnabled: true
    environment: prod
    requiredGroupMembership: []
    providerVersion: V1
    permissions:
      READ:
      - admin
      WRITE:
      - admin
    accountId: 'XXXXXXXXXX'
    regions:
    - name: ap-northeast-1
    assumeRole: role/spin-managed-test
.....

How can I use the lambda feature with account permissions enabled?