When using Parallel task type, failed validation when using Fn:GettAtt for lambda arn for either of the branches

[Wibberley]

Error

[400] CreateStateMachine <= Invalid State Machine Definition: ''SCHEMA_VALIDATION_FAILED: Expected value of type [STRING] at /States//Branches[1]/States//Resource''

****: { Type: "Parallel", Next: "****", Branches: [ { StartAt: "****", States: { GetToUserData: { Type: "Task", InputPath: "$.detail.toUserId", Resource: { "Fn::GetAtt": ["****", "Arn"], }, ResultPath: "$.toUserDetails", End: true, }, }, }, { StartAt: "****", States: { ****: { Type: "Task", InputPath: "$.detail.fromUserId", Resource: { "Fn::GetAtt": ["****", "Arn"], }, ResultPath: "$.fromUserDetails", End: true, }, }, }, ],

This deploys fine to AWS