If you click on help in manager or administrator then click help and about you will see the RMS version. 2.0.2022 is the current. If you don't see the serial number on your receipt you will need to modify the 40 column receipt XML that is in the receipts folder.
**Make and store a backup copy of the receipt before attempting please**
If you create a custom receipt using the default 40 column receipt xml that was installed with RMS open the receipt in notepad, then look for this line.
You will find <SUB name="PrintTransactionDetails"> definition in it,
and there will be a loop like <FOR each="entry">, which loops through all
Transaction entries (ie. Items soled in a transaction).
Add the following where you wish to see the serial Number.
This code will add the serial number in a separate row but you can modify
this to add it anywhere,
<IF>
<CONDITION>Len(ENTRY.SERIALIZED.NUMBER1)</CONDITION>
<THEN>
<ROW>"|S/N." ENTRY.SERIALIZED.NUMBER1 "|"</ROW>
</THEN>
</IF>
If your unfamiliar with editing XML you may want to work directly with a Microsoft Partner or open a support request so them may modify a receipt for you. I hope this helps you.