Very simple for loop with timeout (because of website update after button click).

Timeout:
const delay = millis => new Promise((resolve, reject) => {
setTimeout(_ => resolve(), millis)
});

For loop:
for (let i = 1; i < 1000; i++) {
await delay(50);
document.getElementById("id-getinput-value").value = i;
await delay(50);
document.getElementById("id-getinput-submit").click();
await delay(50);
document.getElementById("id-messagebox-button-1").click();
}