I use the official Fjallraven because it fits as designed: https://www.amazon.com/Fjallraven-Kanken-Organizer-Insert-Backpacks/dp/B082PQZQWY

Tech pouch is whatever you have or prefer, although, Fjallraven has a good one: https://www.fjallraven.com/eu/en-gb/bags-gear/accessories/wallets-small-bags/gear-bag