In this example...
const value = document.querySelector('[data-value]');
const state = document.querySelector('[data-state]');
new Between(1, 10).time(5000).easing(Between.Easing.Cubic.InOut)
.on('update', v => {
value.innerText = `value: ${v.toFixed(2)}`;
}).on('start', () => {
state.innerText = 'state: running';
}).on('complete', () => {
state.innerText = 'state: complete';
});