sendgrid.go: error:net/http: Client Transport of type init.failingTransport doesn't support CancelRequest; Timeout not supported; response:<nil>

sg := sendgrid.NewSendGridClientWithApiKey("string")
    email := sendgrid.NewMail()
    email.AddTo(req.Email)
    email.SetSubject("Confirm your registration at domain")
    email.SetFrom("noreply@domain.com")
    email.SetFromName("domain")
    email.SetText(url)
    if r := sg.Send(email); r == nil {
        log.Infof(ctx, "email sent")
    } else {
        log.Errorf(ctx, "email not sent %v", r)
        w.WriteHeader(http.StatusInternalServerError)
        return
    }