what is problem with fetching currency data in github?

let a= async function d(frm,to){
let c = await fetch('http://api.exchangeratesapi.io/v1/latest? 
access_key=77bdf9458124569180fd15fdab79f07f')
return await c.json()
}

a(frm,to).then(value=>{
    return value.rates}).then(data=>{
        if((data[to]/data[frm]).toString().length===1){
            output.value=`${(amount*(data[to]/data[frm])).toFixed(2)}`;
            console.log(data[to]);
        }
        else{
        output.value=`${amount*(data[to]/data[frm]).toFixed(2)}`;
        console.log(data[to]);
        }
    })

I am working on currency converter i have used api for that my code above works properly and i am getting output correctly but i am not getting output when i have published it on git hub.Error is shown below in the imagethis is error