IHttpContextAccessor returned null in / Scheme and Host

Question

I have a job with a schedule inside this jobs I need to send an email every 5 min so I inject my service to get the data the difficulty is I need to send the link of the application inside email so here obligatory to use IHttpContextAccessor inside my class I injected this to access to context so this my code

    private readonly IService _Service;
    private readonly IHttpContextAccessor _contextAccessor;
    private readonly ILogger _logger;

    public SendEmailOverdueJob(Service Service, ILogger logger, IHttpContextAccessor contextAccessor)
    {
        _contextAccessor = contextAccessor;
        _logger = logger;
    }

    public Task Execute(IJobExecutionContext context)
    {
        IEnumerable<ViewModel> Detail = null;

        Detail = _Service.TaskOverdue();

        if (Detail != null)
        {
            foreach (var item in Detail )
            {
                EmailModel viaEmailModel = new EmailModel()
                {
                    ToName = item.FullName,
                    ToEmail = item.Email,
                    Subject = ConstantStrings.CreatedSubject,
                    FromEmail = null,
                };
                var htmlstring = GetEmailTemplete(ConstantStrings.DocumentRequestFromCreateHtml);
                htmlstring = htmlstring.Replace("[toName]", Convert.ToString(item.FullName));
                htmlstring = htmlstring.Replace("[TITLE]", Convert.ToString(item.Subject));
                htmlstring = htmlstring.Replace("[subject]", ConstantStrings.CreatedSubject);
                htmlstring = htmlstring.Replace("{detailPageLink}", _contextAccessor.HttpContext.Request.Scheme + "://" + _contextAccessor.HttpContext.Request.Host.ToString() + "/Request/Details?id=" + item.Id);
                viaEmailModel.Body = htmlstring;
                viaEmailModel.Body = htmlstring;
                var res = EmailSender.SendEmail(viaEmailModel);
            }
        }
        return Task.CompletedTask;
    }
    public string GetEmailTemplete(string templateName)
    {
        try
        {

            if (!String.IsNullOrEmpty(templateName))
            {
                var path = Path.Combine("wwwroot", "EmailHtmls");
                var filePath = Path.Combine(path, templateName);
                var htmlString = System.IO.File.ReadAllText(filePath);
                htmlString = htmlString.Replace("{emailLogo}", _contextAccessor.HttpContext.Request.Scheme + "://" + _contextAccessor.HttpContext.Request.Host.ToString() + "/images/emaillogo.png");
                return htmlString;


                return htmlString;
            }
        }
        catch (Exception ex)
        {
            _logger.LogError("Error - {exception_source} occured at {exception_datetime}", ex.ToString(), DateTime.UtcNow);
        }
        return String.Empty;
    }

the probleme is _contextAccessor.HttpContext.Request.Scheme & _contextAccessor.HttpContext.Request.Host.ToString() returned null