Custom BO Service integration Issue

Hello,

I followed this blog for my case

This is my custom BO :

This is the xml instance I got for testing

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ns1:LetteringItemIntegrationXMLInputRequest xmlns:ns1="http://0050040694-one-off.sap.com/YURZR4NBY_">
	<MessageHeader>
		<CreationDateTime>2021-06-15T00:00:00+02:00</CreationDateTime>
	</MessageHeader>
	<List>
		<LetteringItem>
			<LetteringItemID>1</LetteringItemID>
			<JournalEntryID>980000011641</JournalEntryID>
			<JournalEntryItemID>1</JournalEntryItemID>
			<GLAccount>
				<CompanyUUID>00163E0D-6B66-1ED8-81A0-E32B113A63E0</CompanyUUID>
				<ChartOfAccountsCode/>
				<ChartOfAccountsItemCode>418000</ChartOfAccountsItemCode>
			</GLAccount>
			<FiscalYear>2019</FiscalYear>
			<SetOfBooks>G1FR</SetOfBooks>
			<Note>test</Note>
			<LetteringGroupe>LET-test-excel-1</LetteringGroupe>
			<CreatedBy>maxime</CreatedBy>
		</LetteringItem>
	</List>
</ns1:LetteringItemIntegrationXMLInputRequest>

Everything is imported without error but no new entry is created...

Anyone knows what am I missing here?

(I tried adding the action codes 04,01 and the complete list indicator but it did not work either)