ETO is the in-game currency that you can earn by doing various tasks throughout London.
You can use ETO to purchase clothing and accessories at any of the clothing stores throughout London. Or you can purchase weapons skins and vehicle skins through your Team menu.
Tech Points can be found all over London. You can use these to unlock new gadgets and tech upgrades.
The premium in-game currency is WD Credits. They can be purchased through the in-game Store or through the Ubisoft Store.
WD Credits can be used to purchase items such as Prestige Operatives, DLC content and cosmetics budles.
You can see how much of each currency you have when you open the menu in-game:
If you have any other questions, please get in touch.