It's also available on other major app stores, including Huawei AppGallery, Xiaomi App Store, OPPO App Store, and vivo App Store. If Microsoft Authenticator isn't available in the app store on your device, try installing one of the app stores listed above first, then download it from there.How to link the authenticator app to your OKX account? Once the app is downloaded, you'll need to link it to your OKX account.