Confusion: POR state and STARTUP state + calbration

We try to utilize either of SX1261/2/8 ICs.
We are not sure if calibration is being done when the SX1261/2/8 powers up.

Regarding the startup stage of the IC. Once it powers up, the datasheet mentions the IC goes into STARTUP state (in section 9.1 in your datasheet(s)). We would expect the STARTUP state to be the POR state.

So Calibration is not taking place when the IC powers on and goes at the STARTUP state? Aka the IC needs to call the calibration command to calibrate after startup?

And the follow up question is, how is POR state entered (if not after power up of the device?). I guess to enter POR, The IC needs to be resetted after it powers up aka after STARTUP state?.

Thank you.