@dflass
someone please correct me if i am wrong, but i believe there is no Qt way of doing this. This has to be done in natively using mobile platform's capabilities.
On android this would be altering the manifest file, on iOS i think you need to overrride UINavigationController. See this and this.

@SGaist Thank you so much, it's my first time with mobile and I'm still working it out. It worked perfectly, and also thank you for answering so quickly!