But you have. From their help:

"What Data does Relai store?

Every time a Relai user makes a transaction through the Relai app, we collect information about the order. The data we collect includes the user’s

Currency (EUR or CHF)

Amount

IBAN

Bitcoin wallet address

Timestamps for order created, executed, exchanged, and payment received

Trade recurrence (once, weekly, or monthly)

Referral code (if applied)

Referral commission

User details for sell orders (which includes first and last name, address, and bank details)

For incoming deposits, we collect the deposit amount, deposit ID, user details, and bank details

All exchange orders we place on our third-party exchange partner

Push notification tokens (if permissions are given in the app)"

Which is an issue, because:

"How can I delete my account?

...

All data related to the use of Relai and especially banking transactions, we must by law keep for 10 years. After that, the data will be deleted automatically."

Linking sats to IBANs with every trade, just waiting for the tax authorities to require all their user data since day one.