FPV drones do not hold hovering position like a GPS camera drone.

But if it is drifting a lot, first make sure all of your transmitter trims are centered. If using the controller from a TinyHawk RTF bundle, repeatedly push the trim buttons in one direction, then the other, until you hear a longer "beep" sound. Every press makes a "beep" sound, but there will be an audibly longer "beep" sound once you reach center.
Next, connect the drone with a DATA USB cable (not just a charging one) to your computer and Betaflight Configurator. Please choose the right Configurator version for your particular drone (check our Knowledge Base articles). For example, if you have the original TinyHawk, follow the steps here to see which Configurator version you need:
TinyHawk RTF/BNF - Manual/Firmware/CLI/Binding for v1/v2
Then, with the drone on a completely level surface, click Calibrate Accelerometer (do NOT click Reset Settings, which just sets the board to generic defaults and will not function without the stock CLI settings):