Hi, old fox! Once a programmer, always a programmer.
Post the code of the current part of Your project/research! Building it, quoted, "building it one part/piece at a time" is the best. Good!
Values of the magnitude of 903300 needs a variable declared as long. You surely recall that all numbers are stored as 0:s and 1:s in the code. The presentation to us can be done in binary, octal, decimal, hexadecimal. All from the same basic variable.
Where the number comes from doesn't matter, keyboard, #define or what.
I don't know the Lora library, how Lora.write(largeValue) works. Check the documentation/example codes around Lora.
Searching for "Arduino + Lora" is what I would try the first. Then look at the links and inspect possible alternatives.