I work on razor page asp.net . I face issue my issue values on get reset after click submit button so when click submit button and check values on POST I found it become null

so How to avoid this behavior OR with another meaning how to retain values on get without reset when click submit button

from my debug details as below

1 - when page load i check user id it have value 9595

   public void OnGet()
    {
        string MyUserData = Request.Cookies["myUserData"];
        UserAuthResponse? userAuthResponse = System.Text.Json.JsonSerializer.Deserialize<UserAuthResponse>(MyUserData);
        string UserID = userAuthResponse.Data.UserID;
    }

2 - Now I will click submit button so break point hit on post method

public async Task OnPost(UC.ADC.Core.Entities.SQL.Branch branch)
{
//userAuthResponse.Data.UserID become null
}

when check values of userAuthResponse.Data.UserID it become null

so how to preserve or retain value of userAuthResponse.Data.UserID after make get
to use it on post method

form view as below :

<form method="post">
       
        <div class="form-group row" style="margin-left:200px;font-size:15px;font-family: 'Open Sans' , sans-serif;font-weight: bold;">
            <button type="submit" class="col-sm-1 btn btn-primary">Submit</button>
            
        </div>
    </form>

issue debug details as below :

Add a public property to your PageModel class that represents the value and apply a BindProperty attribute to it. Then add a hidden field to your form that contains the value you want to persist across requests:

[BindProperty]
public string UserID {get;set;}
public void OnGet()
{
    string MyUserData = Request.Cookies["myUserData"];
    UserAuthResponse? userAuthResponse = System.Text.Json.JsonSerializer.Deserialize<UserAuthResponse>(MyUserData);
    UserID = userAuthResponse.Data.UserID;
}

Then the form:

<form method="post">
    <input type="hidden" asp-for="UserID" />
    <div class="form-group row" style="margin-left:200px;font-size:15px;font-family: 'Open Sans' , sans-serif;font-weight: bold;">
        <button type="submit" class="col-sm-1 btn btn-primary">Submit</button>
    </div>
</form>

The posted value should automatically get bound to the public property.

This is one of many state management strategies for persisting values across HTTP requests: https://www.learnrazorpages.com/razor-pages/state-management