Hi, just got my oven. Doing self installation, wiring had done by contractor.
The oven come with wire w/o plug.
My question is, can we connect the wire via the wire connector(those with screw on top and join then screw it) or I need to remove the oven wire and connect direct from wire to the oven connector terminal.

No, wow. They just lay the wire, said it can direct connect with the oven. Because my oven only arrive after 4 months renovated.
He just make a 20A switch control the power.

Basically you should seperate oven and the induction cooker.
both must be use 20Amp. Your electrician should make a new wire for two fuse. Same like air con and heater where each fuse is dedicated to each appliances.
But I share my oven with my microwave, since oven is seldom use and microwave as well. But both are share in 20AM fuse.