Adding custom policies and arguments to Chromium is supported using the following Advanced Player Directives:

• chromium_args
  You can provide a list of arguments to remove and a list of arguments to add to the final Chromium command. The value of the directive must be a valid JSON. Removal of arguments precedes the addition. For example:
  
  chromium_args={"remove": ["--kiosk"], "add": ["--my-new-argument", "--another-arg"]}
• chromium_policies
  You can provide a JSON with Chromium policies with this directive. Available policies are available here and here. For example:
  
  chromium_policies={"PolicyName": "PolicyValue", "SomethingElse": 0}

  By default on Buster only the default policies used are currently the following:

{
"PasswordManagerEnabled" : false,
"PluginsAllowedForUrls" : [
"https://", "https://"
]
}