Connecting an induction cooker to a regular socket, cable 2.5 mm sq.

As if in two ways. The panel is like an electric stove, and since it is an electric stove, then you need a separate cable and a separate automatic machine, and the cable is recommended at least 6 mm², this is in accordance with SP 31.110 and its updated editorial offices.

However, hobs are different, apparently you have a small one, maybe for 2 burners, apparently it consumes less than 3.5 kW of power. Is it originally equipped with a plug? If yes, then it is reasonable to connect directly to the outlet, if not, then see the power of the stove, count the current, for this you need to divide the power by voltage.

The standard socket is designed for 10-16A, which means that you can connect devices with a power from 2.2 to 3.5 kW (depending on which outlet, basically all modern ones are designed for 16A and 3.5 kW respectively).

If your stove consumes more, lay a separate line and connect the cable directly or through a special socket for the electric stove. Such sockets are larger, usually plugs for them with rectangular pins and can withstand a current of 25 amperes (and more) ...