lender will require it if you have loan

The HOA insurance covers the structure and basic internal configuration (builder-grade floor- which will be cheap carpet, builder-grade cabinet, counter, bath...).

Your own insurance covers the upgrade (maple cabinet, granite counter...., better appliances, better floor-wood, laminate, top-grade carpet if any, tile...), plus personal properties in the condo, if any (refrig, washer/dryer...)