Login in google spreadsheet whats wrong

Hello, I am trying to make a signup and login page in appinventor using spreadsheet, and i was following a video,
but idk why when i try to save the script for the spreadsheet, it says this message.

its in korean so it says error: SyntaxError: Illegal return statement line: 66 file: Code.gs
what should i do?
Thanks in advance!

function doGet(e) {

return Authentication(e);

}

function doPost(e) {

return Authentication(e);

}

function Authentication(e) {

if (e.parameter.func == "Create") {

var ss = SpreadsheetApp.openById(e.parameter.ID);

var sh = ss.getSheetByName(e.parameter.SH);

var rg = sh.getName() + "!" + sh.getDataRange().getA1Notation();

var email = e.parameter.email

var sql = '"Select B where B=''+email+''"';

var qry = '=IFERROR(query(' + rg + ',' + sql + '),"")';

var ts = ss.insertSheet();

var setQuery = ts.getRange(1,1).setFormula(qry);

var getResult = ts.getDataRange().getValues();

ss.deleteSheet(ts);

if (getResult==""){

var data=[e.parameter.name, e.parameter.email, e.parameter.password, e.parameter.batchnumber];

sh.appendRow(data);

return ContentService.createTextOutput(getResult);}

}

}

//------------------------------------------------------------------------

if(e.parameter.function =="Login"){

var ss = SpreadsheetApp.openById(e.parameter.ID);

var sh = ss.getSheetByName(e.parameter.SH);

var email = e.parameter.email;

var password = e.parameter.password;

var rg = sh.getName() + "!" + sh.getDataRange().getA1Notation();

var sql = '"Select A,B,C where B=’’+email+’’"';

var qry = '=IFERROR(query(’ + rg + ‘,’ + sql + ‘),"")';

var ts = ss.insertSheet();

var setQuery = ts.getRange(1,1).setFormula(qry);

var getResult = ts.getDataRange().getValues();

var getPWD = ts.getRange(1,3).getValues();

var getFullName = ts.getRange(1,1).getValues();

ss.deleteSheet(ts);

if (getResult!=""){

if (getPWD==password){ return ContentService.createTextOutput( getFullName);}

else { return ContentService.createTextOutput("ERPWD");}

}

else{return ContentService.createTextOutput(getResult);}

Someone else recently had trouble with this script from that video.

Try this instead ?