Task AzureDevTestLabsCreateVM cannot handle key vault reference in the arm template

I'm trying to call task AzureDevTestLabsCreateVM in my yaml pipeline. I pass in the arm template and parameter file to the task. For sensitive parameters such as SAS token or password, I store them in key vault and reference the key vault in the parameter json file. For demo, I use the example json from https://docs.microsoft.com/en-us/azure/azure-resource-manager/templates/key-vault-parameter?tabs=azure-cli :

{
"$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentParameters.json#",
"contentVersion": "1.0.0.0",
"parameters": {
"adminPassword": {
"reference": {
"keyVault": {
"id": "/subscriptions//resourceGroups//providers/Microsoft.KeyVault/vaults/"
},
"secretName": "ExamplePassword"
}
}
}
}

However, the task give me this following error:
[error]Error => code: 'undefined'; message = 'Cannot read property 'toString' of undefined'

I then dug into the source code, and here is what I found:
https://github.com/Azure/azure-devtestlab/blob/cbca7792cbb717cf9dc613e1569f2dd7ce5cf546/tasks/Node/src/modules/task-utils/deployutil.ts#L96

This piece of code seems it only handles 'value' of parameter, and not 'reference', although 'reference' is allowed according to the schema.