Yes, you can! You don't need to be with a specific energy supplier or have a special tariff to take part in the DFS equivents with equiwatt.
Although you don't need to be with a specific energy supplier or have a special tariff to take part in the DFS equivents with equiwatt, you will need a compatible smart meter and half-hourly data available to receive points for participating in DFS equivents.
TIP: The easiest way to check if your smart meter is compatible and working in smart mode is to use the free smart meter checker by Citizens Advice.
You can use their checker here - https://smartmetercheck.citizensadvice.org.uk/
To find out if your smart meter is compatible and sends half-hourly data, sign up to the app, follow the steps to validate your MPAN and connect your smart meter, you can find out within hours or up to 3 days (if it takes a bit longer for your smart meter data to appear).