Fix

[jagged gale]

How I can fix it?

import { ActionFormData } from "@minecraft/server-ui"
import { world, system } from "@minecraft/server"

let form = new ActionFormData ();
form.body("Example Body")
form.title("Example Title")
form.button("Example Button")

world.afterEvents.itemUse.subscribe(eventData=>{
let player = eventData.source
form.show(player)
})

[upper zodiac]

import { ActionFormData } from "@minecraft/server-ui"
import { world, system } from "@minecraft/server"

function f(player) {
    let form = new ActionFormData ();
    form.body("Example Body")
    form.title("Example Title")
    form.button("Example Button")
    form.show(player).then((r)=>{
        if (r.canceled) return
        if (r.selection == 0) {
            world.sendMessage(`Example Button`)
        }
    })
}

world.afterEvents.itemUse.subscribe(eventData=>{
    let player = eventData.source
    f(player)
})

[jagged gale]

Thanks, where is the my problems?

When i go home, I try it

[upper zodiac]

You don't have any problem, it's just that your declaration is not optimal and lacks event binding to the buttons.

[jagged gale]

What did I ultimately need to change?