If you own Huawei Watch GT, Watch GT 2, Watch GT 2e or Watch GT 2 Pro you can use it also with your iPhone. But Huawei Health application for iOS is different than Android version, so i recommended to check it before you purchase it.
Most of the features works without problems, i will attach some screenshots from Apple iPhone 12 Mini and you can compare it with your version. Which Huawei Watch features are not available for iOS users? You cannot install new custom watchfaces and you cannot buy new watchfaces (but you can download many free watchfaces). You are also not able to transfer music to Huawei Watch GT 2, Watch GT 2e and Watch GT 2 Pro. And if you are using the latest Huawei Watch GT 2 Pro, you are also not able to install new apps.
And one more thing – Apple Watch comes with many interesting features and together with iPhone it just works, but i don’t like it so much thanks to design, battery life and prize. What is important – we have many interesting smartwatches on the market, so perfect situations for customers.