Deploy azure automation variables using arm template, got following errors:Status Message: {"Message":"Invalid JSON - Kindly check the value of the variable."} (Code:BadRequest)

[hsszlll]

My arm template content:
{
"name": "[variables('automationAccountName')]",
"type": "Microsoft.Automation/automationAccounts",
"apiVersion": "2022-08-08",
"location": "[variables('location')]",
"identity": {
"type": "UserAssigned",
"userAssignedIdentities": {
"[variables('userAssignedIdentityResourceId')]": {}
}
},
"properties": {
"sku": {
"name": "Basic"
}
},
"dependsOn": [
"[resourceId('Microsoft.ManagedIdentity/userAssignedIdentities', variables('userAssignedIdentityName'))]"
]
},
{
"type": "Microsoft.Automation/automationAccounts/variables",
"apiVersion": "2022-08-08",
"name": "[concat(variables('automationAccountName'), '/', 'test')]",
"properties": {
"description": "test",
"isEncrypted": false,
"value": "test"
},
"dependsOn": [
"[resourceId('Microsoft.Automation/automationAccounts/', variables('automationAccountName'))]"
]
}

Errors: