Anker Power Bank, 5,200mAh Ultra-Compact Portable Charger, 321 (PowerCore 5K), Compatible with iPhone 13 and 12 Series… Price:  £19.99 (as of 08/04/2023 20:40 PST- Details)

Make sure this fits by entering your model number.
Perfectly Portable: Easily carry the 321 Power Bank with you wherever you go thanks to its ultra-compact and lightweight design.
Small Size, Big Power: This compact 5,200 mAh portable charger is able to power iPhone 13 once.