Arduino for STM32

Using the new bing chatbot I got this function that magically manages to put the STM32F401 in DFU mode. However, I've already tried doing this in the chatbot again and it can't reproduce the same code, and it even says that the code doesn't work when I show it what it created for me. LOL.
But yes ...

I don't know if I'm asking the question in the correct post, but I searched and didn't find this answer.
Is there a way to make the STM32F401 enter DFU mode through commands? ie: enter DFU mode via software.

example: AndrewBCN https://www.stm32duino.com/memberlist.php?mode=viewprofile&u=1395

https://www.stm32duino.com/viewtopic.php?f=41&t=1030&p=6899&hilit=LL_GPIO_SetPinMode#p6899
It was possible to count in PA15 frequencies between 1Hz to just over 40MHz using an external clock of 1Hz in PB10 ...

Guys, I'm new here.
Is there a way to measure more than 3MHz using the STM32F4?
In this example the person can measure 3.2MHz using ATMEGA328
https://forum.arduino.cc/t/counting-falling-edge-events-of-a-4mhz-input-signal/509476/21?page=2

//TCNT1 16 bit max value = 65,534
//20ms sample period gives ...