Help with the "update_data_flags" API call

I'm reading through the documentation part of "Item events management" to get the events from a unit using it's ID, i try it just like this:
"https://hst-api.wialon.com/wialon/ajax. … p;params={"spec:[{"type":"id","data":*UNIT_ID_HERE*,"flags":4611686018427387903,"mode":0}]}&sid=MY_SID"
I try this and it gives me a response, i havent identify what all the data means yet, but right now my question is this one: This API when i try it on my browser it works fine, but when i try to use this API call using php nothing happends not even an error message, as an example this is the line of code where i put the request: 
$CALL = $wialon_api->update_data_flags('{"spec":[{"type":"id","data":UNIT_ID_HERE,"flags":4611686018427387903,"mode":0}]}');
this is where i suspect the problem is but as far as i know theres nothing wrong with this.
sorry if its a very technical question but im just very confused unless im doing something wrong.

Thank you, any help is very appreciated