I think it’s set to 5V because I uploaded the code to Arduino UNO without any external power supply.
You need to confirm this with a multimeter or better yet, get a know working FTDI board like this exact same one:
https://www.sparkfun.com/products/9716
Do you think that the URA application is not able to find COMS…there might be a path location, sketch location something like in the Arduino IDE we are providing sketchbook location…???
No, none of those things would cause the URA to not find a COM port.
What about Raspberry Pi 3, I am still getting Time out error…
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You need to forget about making things work with a pi until after you get it working in Windows.
I strongly suggest you exactly duplicate the parts used in the SparkFun guide or known working parts. If you’re using the wrong voltage USB to serial adapter, your board will never work no matter what you try.