Install pre release python packages via databricks API

How can I install pre release python packages via databricks api?

I'm using databricks API to install packages, like this:

{
 "cluster_id":"10201-my-cluster",
 "libraries":[
  {
     "pypi":{
        "package":"simplejson==2.1.*",
        "repo":"https://my-pypi-mirror.com"
     }
  }
 ]
}

Only stable versions are installed on the cluster.

I want something like this:

{
 "cluster_id":"10201-my-cluster",
 "libraries":[
  {
     "pypi":{
        "package":"simplejson==2.1.*",
        "repo":"https://my-pypi-mirror.com".
        "pre-release": true
     }
  }
 ]
}

I'm using --pre flag to install pre release packages in my machine, but I don't know how can I do it in databricks.

I wanted to avoid having to install packages through init scripts.