Make hidden Input.ChoiceSet required if toggled to visible - power-automate

Question

New to Power Automate and adaptive cards. I have an approval process where the card can be approved, rejected or reassigned. Clicking the Reassign button reveals the Input.ChoiceSet element. I wish to then make the Input.ChoiceSet field required if it is visible, is this possible?
I can set the Input.ChoiceSet as required but this then impacts the other actions on the card.
Below is my json:
{
"type": "AdaptiveCard",
"$schema": "http://adaptivecards.io/schemas/adaptive-card.json",
"version": "1.3",
"body": [
{
"type": "TextBlock",
"text": "Change Request",
"wrap": true,
"id": "lblHeader",
"size": "Large",
"weight": "Bolder",
"color": "Default"
},
{
"type": "TextBlock",
"text": "Company",
"wrap": true,
"id": "lblCompany",
"separator": true,
"size": "Medium",
"color": "Accent",
"weight": "Bolder",
"horizontalAlignment": "Center"
},
{
"type": "ColumnSet",
"columns": [
{
"type": "Column",
"width": "stretch",
"items": [
{
"type": "TextBlock",
"text": "Current Owner:",
"wrap": true,
"id": "lblCurrentOwner",
"weight": "Bolder"
},
{
"type": "TextBlock",
"text": "New Owner:",
"wrap": true,
"weight": "Bolder",
"id": "lblNewOwner"
}
]
},
{
"type": "Column",
"width": "auto",
"items": [
{
"type": "TextBlock",
"text": "X",
"wrap": true,
"id": "txtCurrentOwner"
},
{
"type": "TextBlock",
"text": "Y",
"wrap": true,
"id": "txtNewOwner"
}
]
}
]
},
{
"type": "TextBlock",
"text": "Please action using the below buttons.",
"wrap": true,
"spacing": "Large",
"id": "lblActions"
},
{
"type": "TextBlock",
"text": "Comments",
"wrap": true,
"id": "lblComment",
"size": "Small",
"color": "Default",
"spacing": "Large"
},
{
"type": "Input.Text",
"placeholder": "Add your comments here",
"id": "txtComments",
"isMultiline": true,
"spacing": "Small"
},
{
"type": "ColumnSet",
"columns": [
{
"type": "Column",
"items": [
{
"type": "ActionSet",
"spacing": "None",
"actions": [
{
"type": "Action.ToggleVisibility",
"title": "Reassign",
"id": "btnReassign",
"targetElements": [
"ddlEmployeePicker",
"asAssign"
]
}
]
}
],
"width": "auto",
"horizontalAlignment": "Center"
},
{
"type": "Column",
"width": "stretch",
"spacing": "ExtraLarge"
},
{
"type": "Column",
"width": "auto",
"items": [
{
"type": "ActionSet",
"actions": [
{
"type": "Action.Submit",
"title": "Reject",
"id": "btnReject",
"style": "destructive"
}
]
}
],
"spacing": "Small",
"horizontalAlignment": "Center"
},
{
"type": "Column",
"width": "auto",
"items": [
{
"type": "ActionSet",
"actions": [
{
"type": "Action.Submit",
"title": "Approve",
"id": "btnApprove"
}
]
}
],
"spacing": "Small",
"horizontalAlignment": "Center"
}
]
},
{
"type": "Input.ChoiceSet",
"choices.data": {
"type": "Data.Query",
"dataset": "graph.microsoft.com/users"
},
"id": "ddlEmployeePicker",
"placeholder": "Type an employee name",
"label": "Assign to:",
"isMultiSelect": true,
"isVisible": false,
"spacing": "Medium",
"errorMessage": "Please provide an employee to reassign"
},
{
"type": "ActionSet",
"actions": [
{
"type": "Action.Submit",
"title": "Assign",
"style": "positive",
"id": "btnAssign"
}
],
"spacing": "Small",
"id": "asAssign",
"isVisible": false
}
]
}
The Input.ChoiceSet in question is ddlEmployeePicker.
Thanks in advance