RAX 4630 - Needs UF2 file for Arduino IDE

Can anybody point me in the right direction to locate this RAX 4630 UF2 file.
When I connect the RAK 4630 to pc and run Arduino’s IDE , press the rest button twice, a New Mass Storage Drive shows up looking for me to drop into this drive the missing UF2 file.

Any ideas where to find it or create it?
Thanks;

There is no UF2 file created by Arduino IDE for RAK4631.

You write your application, compile it with Arduino IDE and flash it. There is no need to double push reset when flashing with Arduino IDE.