<apex:page lightningStylesheets="true" standardController="Acquisto__c" extensions="CassaInputFieldCnt" docType="html-5.0">           
    <script  type="text/javascript" src="http://ajax.googaleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js"></script>
    <script  type="text/javascript">
    	function aggiornaQnt(val,id){         
        	console.log(val);
        	console.log(id);
        }
    
    	$("#qnt").bind('keyup mouseup', function () {
                console.log("changed");            
        });
    </script>


<apex:inputText html-min="1" html-type="number" value="{!qnt}"  onclick="aggiornaQnt(this.value,'{!sa.id}');" style="width:80px!important;" />