Google Apps Script that copies rows to a new sheet based on a cell value.

moveRows.gs

function onOpen(e) {
  let ui = SpreadsheetApp.getUi(); 
  ui.createMenu('🤖 Automation Tools')
    .addItem('Move reps to individual sheets', 'moveRows')
    .addToUi(); 
}; 

function moveRows() {
  const ss = SpreadsheetApp.getActiveSpreadsheet(); 
  const sheet = ss.getActiveSheet(); 
  const eddieSheet = SpreadsheetApp.openById('1wvrKeJd2zj3_tT1W0jkXoIZEbGf4_-0SSSesRgtK_Og').getSheetByName('Sheet1'); 
  const eddieLastRow = eddieSheet.getLastRow(); 
  
  const josephSheet = SpreadsheetApp.openById('1U0xTv-0_dyFsF3AwwDzT86cjqySjnJcZkn4d4n0MZ1k').getSheetByName('Sheet1'); 
  const josephLastRow = josephSheet.getLastRow(); 

  let lastRow = sheet.getLastRow(); 

  let sortRange = sheet.getSheetValues(2,1,lastRow, 4); 

  Logger.log(lastRow)
  // Logger.log(typeof(sortRange))
  // Logger.log(sortRange.length); 

  let josephCounter = 1; 
  let eddieCounter = 1; 

  for (var i = 1; i <= sortRange.length; i++) {
    let name = sheet.getRange(i,1).getValue(); 
    console.log(i + " - " + name); 

      if (name == "Joseph Palumbo") {
        let rowValues = sheet.getRange(i, 1, 1, 4).getValues();
        josephSheet.getRange(josephLastRow+josephCounter, 1, 1, 4).setValues(rowValues); 
        josephCounter++; 
      }

      if (name == "Eddie Jauregui") {
        let rowValues = sheet.getRange(i, 1, 1, 4).getValues();
        eddieSheet.getRange(eddieLastRow+eddieCounter, 1, 1, 4).setValues(rowValues); 
        eddieCounter++; 
      }
  }; 
}; 

I am totally new to writing scripts, so thanks in advance for your patience. When I try to run this script on my master sheet, I get "TypeError: Cannot read properties of null (reading 'getLastRow')"

Any advice? Thank you!