Url to add a related record in different app, save and return to first app

Hello QB Community,

We manage our travel / vacation using one app and our labor allocation using a separate app.

I would like that when you schedule travel or vacation in the first app, it shows up in the second app as a related record that is going to consume 8 hours of a person's time per day. 

Two Apps: 
Attendance: dbid: bkkc9ccd4
Labor: dbid: bijtsh3fr

I set up the relationship in attendance, to save  when a child record is added. 

Then I have this URL:
var text DisplayRecord=URLRoot() & "db/" & "bkkc9ccd4";


var text AddRecordOne =
URLRoot() & "db/" & "bijtsh3fr"& "?a=API_GenAddRecordForm&dfid=2&_fid_181="&URLEncode([Activity ID])&"&_fid_9="&URLEncode("J145899")&"&z="
&"&_fid_17 ="& Today()
&"&_fid_22 ="& Today();


var text save =URLRoot() & "db/" & "bijtsh3fr" &"?a=dr&r=edu";

$AddRecordOne & "&rdr=" & URLEncode($save) 


But it does not work, it errors out all the time. 

Does anyone know of a way to do this?