Hi @芹沢 基樹
The output of Get-AzLogicAppRunAction will be an array of WorkflowRunAction. You can iterate through the array value for the property Error. You need to check the HasValues field to know if the object contains the error and message details or not.
$WorkflowRunActionArray = Get-AzLogicAppRunAction -Name testmak -ResourceGroupName logicapptest -RunName 08585867709937474078259108588CU31
$ErrorDetails = $WorkflowRunActionArray[0].Error
Below is the output of $ErrorDetails and check the HasValues field and iterate to other fields inside the object.
HasValues : False
Type : String
Parent : {}
Root : {code, message}
Next :
Previous :
Path : code
First :
Last :
LineNumber : 0
LinePosition : 0
HasValues : False
Type : String
Parent : {}
Root : {code, message}
Next :
Previous :
Path : message
First :
Last :
LineNumber : 0
LinePosition : 0