Help with Creating First Record in Empty Table via Button in Ninox

Fred it gives me an error on the first line that the table "New Months Report"is not found. but it is enough for me to create the first record, without copying old records, specify the date in the field 

newRec.('Beg Date' := today());

Fred it is necessary to clarify that a table New Monts report is a subtable in a table EMPLOYEES. and there is no record in it when we create a new employee, but old employees have records there

the error disappeared there but it appeared on line 3, 4  and 5, in the third table not found

Fred 
it is necessary that the button creates the first entry in the table. The button that will then make the next one if necessary is there, and it works well, the problem is in the first entry. Basically, all entries in this table should be made by the button, so view will be displayed, to remove the "Create record"

Fred No matter how many records there are in the table, when creating a new employee, his table will be empty, that's the problem for me. When there is at least one record for an employee, I have a button that creates the next record, transferring the information I need that we rarely change

let t := this;
let oldData := last('New Months Report' order by 'Beg Date');
let newRec := duplicate(oldData);
delete newRec.'LIST OF PROMOTION';
delete newRec.ADVANCE;
let x := if month(oldData.'Beg Date') = 12 then
        date(year(oldData.'Beg Date') + 1, 1, 1)
    else
        date(year(oldData.'Beg Date'), month(oldData.'Beg Date') + 1, 1)
    end;
newRec.('Beg Date' := x);
newRec.('End date' := date(year('Beg Date'), month('Beg Date') + 1, 0))

Fred Good morning

In the table  new month report there are many fields, I need a button that will create a first record in the table new month report , indicating only the date of creation in the field Beg Date

Table new month report field Beg Date is configured so that through triggers field End Date receives the end of that month.
When we create a formula that can do this, we will add a function that if the table already has a record, then do

let t := this;
let oldData := last('New Months Report' order by 'Beg Date');
let newRec := duplicate(oldData);
delete newRec.'LIST OF PROMOTION';
delete newRec.ADVANCE;
let x := if month(oldData.'Beg Date') = 12 then
        date(year(oldData.'Beg Date') + 1, 1, 1)
    else
        date(year(oldData.'Beg Date'), month(oldData.'Beg Date') + 1, 1)
    end;
newRec.('Beg Date' := x);
newRec.('End date' := date(year('Beg Date'), month('Beg Date') + 1, 0))

This allows you to move some data from the previous month.

Fred there is a table EMPLOYEES in which the button is located and there is also an internal table New Months Report. DB which I loaded, everything as I described now. And the button which is outside the table New Months report should create the first record in the table by defining the command for the field Beg Date date today()

Fred Hello