hi @msfujino ,
In my project am also using PA13,PA14 to flash the sketch with the help of ST_LINK it will be Running successfully. In my custom board PC0,PC1 uart pin are used for serial monitoring the output. In case by using this PC0,PC1 uart pin I need to change any updates for your example code . Is it possible to Monitor the serial print by using this. or Any other possibilities are there to monitor the output.