New Modern Page by AzureFunction

// parse query parameter
string siteURL = req.GetQueryNameValuePairs()
    .FirstOrDefault(q => string.Compare(q.Key, "siteURL", true) == 0)
    .Value;

string pageName = req.GetQueryNameValuePairs()
    .FirstOrDefault(q => string.Compare(q.Key, "pageName", true) == 0)
    .Value;

// Get request body
dynamic data = await req.Content.ReadAsAsync<object>();

// Set name to query string or body data
siteURL = siteURL ?? data?.siteURL;
pageName = pageName ?? data?.pageName;

OfficeDevPnP.Core.AuthenticationManager am = new OfficeDevPnP.Core.AuthenticationManager();
using (var cc = am.GetSharePointOnlineAuthenticatedContextTenant(siteUrl, userName, secpass))
{
  bool pageMissing = false;
  try
  {
      ClientSidePage.Load(cc, pageName);
  } catch(Exception ex1)
  {
      pageMissing = true;
  }

  if (pageMissing)
  {
      ClientSidePage newPage = new ClientSidePage(cc);
      newPage.LayoutType = ClientSidePageLayoutType.Article;
      newPage.Save(pageName);
      log.Info("Site Page is created");
  }