I am releasing the Board Manager for MINHF4. There are 2 choices, but before going both ways, you have to install STM32 Cores from ST first by using this JSON Link and put it into Preferences menu:

https://github.com/stm32duino/BoardManagerFiles/raw/master/STM32/package_stm_index.json

Then, you can install MINHF4 board by these 2 ways:

The first one is to put this JSON Link into your Preferences in Arduino and it should be in the Board Manager of Arduino IDE:

https://raw.githubusercontent.com/minh7a6/MINHF4/master/Releases/package_minhf4_index.json

The second way is to install manually by downloading my MinhF4 Github and copy "MinhF4" folder inside "Release" folder into Hardware folder in Arduino.

Anyways, Happy Valentine!!