For reference, you can do it by :
1. Select "Coins" tab
2. Click "Amount" to sort by value for easier selection
3. Hold "Ctrl" button, then choose all UTXO you want to use
4. Right click on any UTXO you choose and select "Spend"
5. Then you should see "Send" tab and proceed to create transaction
On a side note, you might want to crop your images. You're exposing few private info such as receiving address & bitcoin amount, this might attract people who want to steal your coins with social-engineering attack.