Looking for Expert who is able to make a Cross Platform Desktop App and NFT Generator Script to GUI App with High Python+NFT+Unity3D Skill

Hello I have python script that generates NFTs from source folders (Layers and Traits and PNGs) and randomly mixes them up with rarity settings to output with JSON Meta as well. Basically I want to use this same logic (common to most generative NFTs) and have a full blown Desktop App I can publish (cross platform required). Either using the python script or the same logic in C# etc. A game engine might work like Unity3D or Visual Studio etc for this but not sure the quickest and easiest way to make it into an App. The main features are really just read input folders and PNGs dynamically, adjust rarity per item in each folder and then generate randomly to output folder as PNGs + Meta JSONs. The UI should be simple and easy for the user to add names and set rarity to each source PNG for Meta output. Please suggest the easiest and fastest way to build a cross platform desktop app with these features so I can publish it easily on Windows/Mac. May add more features later like export different metas for different cryptos later on default is just eth type. or other helpful features, etc. published app should not have any anti-virus issues and ideally can be published in windows/mac stores as well. Please write "Python + NFT + Unity Skill is my main skill!" on top of bid. Thanks.