Answers for "is settimeout a callback fucntion"

await setTimeout

function timeout(ms) {
    return new Promise(resolve => setTimeout(resolve, ms));
}
async function sleep(fn, ...args) {
    await timeout(3000);
    return fn(...args);
}

settimeout function

setTimeout(function(){ 
$('#overlay'). modal('hide') 
}, 5000);
//#overlay will be the ID of modal which you want to hide or show modal