Add up what your belongings would cost to replace.
Most people underestimate what's inside their home. Go room by room and enter roughly what it would cost to replace your things new today, not what you could sell them for.
The total gives you a number to compare with the contents limit on your policy. You can copy the list to keep with your insurance records. Many policies cap jewellery, art and collectibles unless you list them.
Nothing you enter is sent or saved. It's an estimate worked out only from your numbers. It isn't advice, a quote or a recommendation.