Unless you modified your Tx to have the 'optional' camera tilt lever it isn't even there, just two empty holes in the back of the Tx case ...... so no lever, no + shape on the end of the lever's shaft, no worries of smashing the potentiometer on the board, and since no lever ...no need to calibrate it in the RC Assistant.
All you will need to calibrate in the RC Assistant is the sticks ..... check mode 1, and check FCC.
Once you are done you will also need to connect the Vision to your PC, run the 'Phantom Assistant', and calibrate the sticks again via the Phantom Assistant.
Both the Vision and TX must be turned on to do this.
This is something you should do every so often if the Vision starts to drift off.
You are basically calbrating the Tx sticks with the RC Assistant, and 'then' calibrating those calibrated sticks to the Vision.
Hopefully we will all eventually be able to use the 'optional' lever again for the Plus.
For some reason DJI saw fit to make it non-operational to tilt the camera on the Plus, relying solely on the app ...which many of us really don't like .... and worse!