To do what you're asking for, your drone would need more than just a 3rd party app.... it would have to have a way to communicate directly with your phone/device. Sorry, but your
Mini 2 does not.
My Mavic Pro Platinum has a switch on the side, in one position it communicates with the RC as normal. In the other position it acts like an AP (wifi access point) to which I can directly connect my phone/tablet via wifi. After that, the DJI Go4 app has on screen joysticks.
I really like that feature, don't use it much but I like for it to be there if I want it. The MPP also has many other features I like that the Fly app generation of dji drones don't have... even better, it does NOT have many of the 'features' (limitations) of the fly app drones.