Crash when executing a jar

That is not how it works, mods must be installed into the .minecraft/mods directory. Mod loaders, such as Forge and Fabric, have an integrated installer, and some mods like OptiFine and Iris do as well. However, that is not the case for the majority of mods meaning they do not include a GUI that would run via the Execute .jar button and are instead installed by placing the files directly into the mods folder as mentioned. If you're unsure how to access your .minecraft directory, please read the article on how to do so.