For consumer products the DMA focuses on companies with at least 45m monthly active users in the EU. They also exempted some categories that might otherwise qualify e.g. the DMA doesn't appear to cover video gaming consoles because they are "special purpose hardware".

You can see the list of covered companies at https://en.wikipedia.org/wiki/Digital_Markets_Act#Identified...

It's basically Apple, Amazon, Google, Meta, Bytedance and Microsoft.