These hobs are often set up for possible use on 3 phase, so typically there will be earth, Neutral, L1, L2 and L3. Many only actually use L1 and L2.
for single phase operation, you link L1, L2 and L3 together with the links provided. I have yet to see one where this information is not printed on a label on the bottom of the hob, so you don't even need the manual.