You’ll earn cashback only if the offer in the ZEN.COM app explicitly says it works in the store’s own app.
If the offer includes a note like “Remember not to share or open the link externally”, the store’s app isn’t supported. In this case, shop through the link shown in the ZEN.COM app so your cashback can be tracked and added to your account.
Some merchants may also show special instructions under the store’s name once you open the offer. Always check these details to confirm whether the store’s app is supported for that specific offer.