Oneplus 7t Pro Maclaren FPS Metre for Games

thaddeusfox wrote:

In the global version of OnePlus phones, the FPS meter is a standard feature across all devices, enhancing the gaming experience by allowing users to monitor performance in real-time. Unfortunately, this useful tool is absent in the T-Mobile versions of the phone. For gamers who rely on this feature to ensure optimal performance, its absence can be a significant drawback. If you're an avid gamer looking for the FPS meter in your OnePlus device, consider exploring the official OnePlus site or visiting their support forums for possible solutions or updates. Additionally, downloading and installing the official Minecraft game can help test and highlight performance issues, prompting necessary updates or adjustments.

OnePlus keeps certain features to devices directly sold by them to gives customers a reason to buy directly from them.  You are using a phone that is beyond end of life on 5+ year old hardware that has been out of its support window for more than 2 years now.  Your best option for mobile gaming would be to buy the latest gaming focused device not sold by carriers.