Compostable bags are now widely available at stores. You do not have to purchase compostable bags to comply with food waste recycling. You could use paper bags, or no bags at all but if you do, it must meet the ASTM D6400 standards. Liners will have a logo indicating they are compostable. They might look something like this:
If you do not know if a plastic bag is compostable, throw it out in the regular garbage!