That why I don't want to make a mod (as you said in your answer), I want an application that applies to all minecraft clients that allows you to have paid and free cosmetics (by giveaways, promo code, time of use and a range of basic free cosmetics). And so far, when I read your somewhat aggressive comment on my post, which I know was not a simple and risky request, I found a person with whom we already have the prototype of the program that works, who came to me of his own free will and who offered me his free help because he wanted to try with me this project which still had no basis 6 days ago and which nevertheless, helped and will help me again afterwards to poff it and try to propose a serious project to the minecraft community, NOT P2W, on this, thank you for having answered anyway and good evening to you :)
edit: when I said aggressive response I meant something like belittling or in a tone that meant "that's stupid LOL, no one is going to want to help you" or something like that
