Version number is very important for us to generate the build(or bundle).
For example:
Your current version number: P_1.0.5
But if you provide the version number is P_1.0.4, Our engineers(manual as of now) will generate the build of the new version as P_1.0.5, and when our engineers push to your app stores the build with P_1.0.5, Apple will not accept because the version already exist.
Open any of your app, you will be able to find here
Enter the same thing what you seen there in the APP BUILD REQUEST.
S means Sandbox
P means Production