How do you send an HTTP POST request using HttpClient in Blazor?

An HTTP POST request can be sent to add new data in the API server using the SendJsonAsync () method provided by the HttpClient class.

Razor

@page "/employee/add"
@inject HttpClient Http

.. .. .. .. .. .. 
.. .. .. .. .. ..

@code {
    Employee emp = new Employee();
    protected async Task CreateEmployee()
    {
        await Http.SendJsonAsync(HttpMethod.Post, "/api/Employee/Create", emp);
    }
}

web API

[Route("api/Employee/Create")]
public void Create([FromBody] Employee employee)
{
    if (ModelState.IsValid)
        this.employee.AddEmployee(employee);
}

I would suggest you check the below link for better understanding:
https://medium.freecodecamp.org/how-to-create-an-application-using-blazor-and-entity-framework-core-1c1679d87c7e