ParamRazorIndex.cshtml

        @page "/razorindex"
        @model WebApplication3.Views.Param.ParamRazorIndexModel

        @addTagHelper *, Microsoft.AspNetCore.Mvc.TagHelpers

        <h1>Param Razor Index</h1>
 
        <hr />
        <div class="row">
            <div class="col-md-4">
                <form asp-action="ParamIndex">
                    <div asp-validation-summary="ModelOnly" class="text-danger"></div>
                    <div class="form-group">
                        <label asp-for="Path" class="control-label"></label>
                        <input asp-for="Path" class="form-control" />
                        <span asp-validation-for="Path" class="text-danger"></span>
                    </div>
                    <div class="form-group">
                        <label asp-for="ApiKey" class="control-label"></label>
                        <input asp-for="ApiKey" class="form-control" />
                        <span asp-validation-for="ApiKey" class="text-danger"></span>
                    </div>
                    <div class="form-group">
                        <input type="submit" value="Create" class="btn btn-primary" />
                    </div>
                </form>
            </div>
        </div>

ParamRazorIndex.cshtml.cs

        using Microsoft.AspNetCore.Mvc;
        using Microsoft.AspNetCore.Mvc.RazorPages;

        namespace WebApplication3.Views.Param
        {
            public class ParamRazorIndexModel : PageModel
            {
                [BindProperty(SupportsGet = true)]
                public string Path { get; set; } = "";

                [BindProperty(SupportsGet = true)]
                public string ApiKey { get; set; } = "";
                public void OnGet(string path, string apiKey)
                {
                    Path = path;
                    ApiKey = apiKey;
                }
            }
        }