https://www.knowyourmobile.com/phones/is-your-xiaomi-phone-s... was the first ddg result.

Or just google it. Pretty common knowledge that the too cheap to be true chinese phones, amazon fires, etc all trade on your personal data to subsidize the device, either overtly with amazon, or less openly in the case of xiaomi, huwei, and dozens of smaller brands of phone, television, and other connected devices.