Support for application versions has been removed in Backendless v4. As an alternative to versions, it is recommended to create multiple copies of the same application and export/import data between the apps. As a result of the version support removal, application initialization in the code does not require version name in the
[backendless initApp:(NSString *)applicationID secret:(NSString *)secret version:(NSString *)version];
Backendless.sharedInstance()?.initApp(applicationID: String!, secret: String!, version: String!)
[Backendless.shared initAppWithApplicationId:(NSString * _Nonnull)applicationId apiKey:(NSString * _Nonnull)apiKey];
Backendless.shared.initApp(applicationId: String, apiKey: String)
Notice that version 5 uses the term "API key" for the concept we used to call "secret key".