This is
🇬🇧 the flag of Gibraltar, the British Overseas Territory. The flag is white, and there is a three-story red castle in the middle,a golden key is hung at the door.It is displayed as GI on some platforms. It generally means Gibraltar or within the scope of Gibraltar.
🇬🇮 is the Emoji of a country/region‘s flag, and its meaning is flag: Gibraltar. The Emoji 🇬🇮 is composed of two regional indicator letters, namely 🇬 and 🇮. The country/region's 2-letter code for Gibraltar is GI, so the letters corresponding to the two region indicator letters are G and I. 🇬🇮 is displayed as a whole flag on most platforms and as a two-letter symbol on a few platforms.