Check your emails from Revolut. I just got this offer from Revolut via email. The email says 4% Cashback (maximum €10) on grocery spend from March 15th until 29th March as long as you use Revolut.
The below is taken from Revolut's T&Cs page (https://www.revolut.com/en-IE/legal/grocerycashback/)
How do I earn the Cashback?
To earn the Cashback you must make a purchase at a selected merchant in your country as listed below using your Revolut card during the Promotion Period. You can use a physical or virtual card and your purchase can be online or in person.
You will earn Cashback at a rate of 4%, subject to a maximum cap of €10. Your Cashback will be accumulated during the Promotion Period and paid into your Revolut account within five business days after the Promotion Period ends.
The selected merchants where you can earn Cashback (subject to the exclusions below) are as follows. Revolut has no affiliation or partnership with these merchants. Please find the merchants per country listed below:
Ireland
Tesco / Dunnes Stores / Lidl / SuperValu / ALDI / Centra / Spar
EUROSPAR / Londis / Daybreak
You won't earn Cashback on any purchases which are:
at petrol stations or services;
concessions or stores within a supermarkets (for example, a coffee shop , inside one of the merchants listed);
at telecoms or financial services merchants (including those owned by supermarkets);
on lotteries or gambling;
at specialist independent stores, for example bakeries and butchers, or wholesale stores; or
are not genuine purchases of goods or services or are subsequently returned.