System.Security.Cryptography.CryptographicException

Question

When I try to encrypt & decrypt sample text in my WebAPI project the message encrypt successfully but in decryption it dose not work . I have already set in my startup.cs => services.AddDataProtection(); Here is error message:

System.Security.Cryptography.CryptographicException: The provided payload cannot be decrypted because it was not protected with this protection provider.

[Route("api/[controller]")]
[ApiController]
public class SecurityController : ControllerBase
{
    private readonly IDataProtector _protector;
    public SecurityController(IDataProtectionProvider protectionProvider)
    {
        _protector = protectionProvider.CreateProtector("SampleKey");
    }


    [HttpGet]
    public IActionResult Get()
    {
        string text = "sample text";
        string protectedtext = _protector.Protect(text);
        string unprotectedtext = _protector.Unprotect(text);
        return Ok(new { text = text, Protected = protectedtext, unprotexted = unprotectedtext });
    }
}