function doGet(request){
 // Change Spread Sheet url
 var ss = SpreadsheetApp.openByUrl("sheeturl");
 var cid = request.parameter.customer_id
 //var cid = 'U29aea6de153dac793b42dd0659e2f878'
 var cidsum = finduser(ss,cid)
 result = {}
 result.customer_id = cid
 result.totalsum = cidsum
 //console.log(result)
 var result = JSON.stringify(result);
 return ContentService.createTextOutput(result).setMimeType(ContentService.MimeType.JSON); 
}

function finduser(ss,cid){
 // Change Spread Sheet url
 var sheet = ss.getSheetByName('Sheet2');
 var values = sheet.getRange(1,1,sheet.getLastRow()).getValues();
//  console.log(values)
 var ind;
 for(i = 0; i < values.length; ++i) {
    if(values[i][0] == cid) {
      ind = values[i][0];
      break;
    }
 }
 //console.log(i)
 score = sheet.getRange(i+1,2).getValue();
 //console.log(score)
 return score
}