Good morning wim
I'm trying to get the _test2.php script to work
but I get the error Warning: file_get_contents (./ data / luft_24data_esp8266-5220886.arr): failed to open stream: No such file or directory in /web/htdocs/www.pomeziameteo.it/home/luftdaten/ws_luftdaten2.php on line 106
I have configured this in my detector
also tried to put the .htaccess file as you recommended but nothing
do you have any idea where am i wrong? 
Thank you
1. Test
http://www.pomeziameteo.it/luftdaten/sensorluft2.php that is an http request in your browser
2. using inspect (right click in most browsers) you can check what happens with the request
3. it is redirected to http
s and by the security definitions
all data is lost.See attached screenshot
So either
you have to have a sensor with enough processing power to process modern https => very unlikely
or
you have to set the .htaccess to not redirect the commands to the luftdaten folder
But when someone wants to check this problem, you have to
1. post the complete .htaccess file
2. and tell us were you put that file on your webserver.
Your current .htaccess (or cPanel settings) still force all http luftdaten folder traffic to https.
All other settings are OK. The ? can be added or left out.
We use that to test, fi.i. with ?some_test=12345
User and Password need not to be set, we use those when for some reason, new users copy your examples and upload other sensor-data.
Then one can add an extra password check.
Wim