Post a Adaptive Card on Team members channel on their Birthday

1. Create a scheduled flow and set the recurrence to daily.

2.  Add 'List Group Members' action from Office 365 Groups connector and select your Team Id.

3. Loop all the Team members using apply to each.

• To get the birth date information Add 'Get User Profile(v2)' action and select 'User Principal Name' in the User section.
• Add condition and write expression to format the users birth date to retrieve only month and date.        

        formatDateTime(outputs('Get_user_profile_(V2)')?['body/birthday'],'MM-dd') is equal to                             formatDateTime(utcNow(),'MM-dd')

• If the above condition is matches, add 'Get User Photo(v2) and select UPN.
• Add a action ''Post a adaptive card in chat or channel' and select your teams channel details.
• Paste the JSON into 'Adaptive card' section which was designed/copied from Designer | Adaptive Cards

{
    "type": "AdaptiveCard",
    "$schema": "http://adaptivecards.io/schemas/adaptive-card.json",
    "version": "1.3",
    "body": [
        {
            "type": "TextBlock",
            "text": "Happy Birthday !!!",
            "wrap": true,
            "size": "Large",
            "color": "Accent",
            "horizontalAlignment": "Center"
        },
        {
            "type": "ColumnSet",
            "columns": [
                {
                    "type": "Column",
                    "width": "stretch",
                    "items": [
                        {
                            "type": "Image",
                            "url": "data:image/png;base64,@{base64(outputs('Get_user_photo_(V2)')?['body'])}"
                        }
                    ]
                },
                {
                    "type": "Column",
                    "width": "stretch",
                    "items": [
                        {
                            "type": "TextBlock",
                            "text": "@{outputs('Get_user_profile_(V2)')?['body/displayName']}",
                            "wrap": true
                        }
                    ]
                }
            ]
        },
        {
            "type": "TextBlock",
            "text": "Have a nice day !",
            "wrap": true
        },
        {
            "type": "Image",
            "url": "https://media0.giphy.com/media/v1.Y2lkPTc5MGI3NjExcGswdGExaWl3NTYyMzNjZ2VkN2piaHI4emVmZjlzdTV5OXdoNDd2eCZlcD12MV9pbnRlcm5hbF9naWZfYnlfaWQmY3Q9Zw/eLp6v4ca9zajMUnFDL/giphy.gif"
        }
    ]
}