Jenkins extended choice parameter plugin retrieve value from Groovy script - jenkins

Question

I am using the Extended Choice Parameter Jenkins plugin. Used the Groovy script provided in the plugin web page, made some changes to it and currently having:
import org.boon.Boon;
def jsonEditorOptions = Boon.fromJson(/{
disable_edit_json: true,
disable_properties: true,
no_additional_properties: true,
disable_collapse: true,
disable_array_add: true,
disable_array_delete: true,
disable_array_reorder: true,
theme: "bootstrap2",
iconlib:"fontawesome4",
"schema":{
"title": "Environments",
"type": "array",
"format":"tabs",
"items": {
"title": "Environment",
"headerTemplate": "{{self.name}}",
"type": "object",
"properties": {
"name" : {
"title": "Environment",
"type": "string",
"readOnly": "true",
"propertyOrder" : 1
},
"Properties": {
"type": "array",
"format": "table",
"propertyOrder" : 2,
"items": {
"type": "object",
"properties": {
"URL" : {
"type": "string",
"readOnly": "true",
"propertyOrder" : 1
},
"User" : {
"type": "string",
"readOnly": "true",
"propertyOrder" : 2
},
"Password" : {
"type": "string",
"propertyOrder" : 3
}
}
}
}
}
}
},
startval: [
{
[
{
"name": "DEV",
"Properties": [
{
"URL": "host:port1",
"User": "user1",
"Password":""
}
]
},
{
"name": "TST",
"Properties": [
{
"URL": "host:port2,
"User": "user2",
"Password":""
}
]
}
]
}
]
}
}/);
return jsonEditorOptions;
I would like to know:
1) When building, based on a selection/input from the user, let's say: DEV. Then the values associated to DEV would be:
- URL: host:port1
- User: user1
- Password: 123456
How can these values (DEV, host:port1, user1, 123456) be obtained and passed as parameters in the Build steps?
2) Is there a way to mask the value of the field Password when it is being entered by the user?