Add data to the bottom of a range - google-apps-script

Question

So I'm currently trying to set up a simple button which moves data from a range into another sheet for future reference. I've got it working if the sheet it is going to contains no information but I wanted to put all of the references into one sheet together.
Is there a way to add to the bottom of a range of data? This is what I have at the moment.
function Addvoucher() {
var ss = SpreadsheetApp.getActiveSpreadsheet();
var target_sheet = SpreadsheetApp.getActiveSpreadsheet().getSheetByName('Meta');
var source_sheet = ss.getSheetByName("Tools");
var source_range = source_sheet.getRange("B9:D9");
var target_range = target_sheet.getRange("S3:U3");
var last_row = target_sheet.getLastRow();
var target_range = target_sheet.getRange("S3" + (last_row + 1) + ":U3" + (last_row + 1));
target_sheet.insertRowAfter(last_row);
source_range.copyTo(target_range);
}

Answer 1

Modification points:
I think that in your script, how about modifying "S3" + (last_row + 1) + ":U3" + (last_row + 1) of target_sheet.getRange("S3" + (last_row + 1) + ":U3" + (last_row + 1)) as follows?
In the current script, for example, last_row + 1 is 2, "S3" + (last_row + 1) + ":U3" + (last_row + 1) becomes S32:U32. In this case, it is required to be S2:U2. I think that this might be the reason of your issue.
Tried this, the issue is there is data in other columns to the left of this "block" of information thus this gets put onto row 100 as its the first available row.
From your replying, I could understand that in your Spreadsheet, the columns except for the columns "U" to "S" has the values and the last row of the columns "U" to "S" is different from other columns.
When above points as reflected to your script, I would like to propose to modify as follows.
From:
var last_row = target_sheet.getLastRow();
var target_range = target_sheet.getRange("S3" + (last_row + 1) + ":U3" + (last_row + 1));
To:
var last_row = target_sheet.getLastRow();
var values = target_sheet.getRange("S1:U" + last_row).getValues();
for (var i = values.length - 1; i >= 0; i--) {
if (values[i].every(e => e.toString() != "")) {
last_row = i + 1;
break;
}
}
var target_range = target_sheet.getRange("S" + (last_row + 1) + ":U" + (last_row + 1));