These are the banks in Luxembourg you can connect to Vault. They connect through Enable Banking; see Connecting a European bank for how that works.
The bank search in the app is always the most up-to-date list. Banks are listed under their official names, which can differ from the brand you know, so try the name of its group or its town too. Still not there? See If your bank is not in the list.
AndBank
Banco Santander
Bankinter
Banque de Luxembourg
Banque de Patrimoines Privés
Banque J. Safra Sarasin
Banque Transatlantique
BGL BNP Paribas
BTG Pactual
bunq
Credit Agricole Indosuez
Deutsche Bank
DiPocket
Eurobank Private Bank
Finductive
Genome
HSBC
iBanFirst
ING
ING Bank
ING Wholesale Banking
Intesa Sanpaolo Wealth Management
Julius Baer
N26
PayPal
RBS International
Revolut
SEB
Société Générale Luxembourg
Spuerkeess
Swissquote Bank Europe
UBS
Union Bancaire Privée
Viva.com
Vivid Money
Wamo
Wise