Adding fields to an object with if-statement in js

Im trying to aggrigate huge array of objects to single object, but my if statements replace each other:

const obj = [];
res.map((el) => {
    if (el.resource.name === "FORM01" && el.name === "cost.ttl") {
        obj[el.resource.name] = { [el.name]:  el };
    }
    if ( el.resource.name === "FORM01" && el.name === "cost.use") {
        obj[el.resource.name] = { [el.name]:  el };
    }
});

in result i wat add in obj[el.resource.name] = {} two fields "cost.ttl" and "cost.use".