Get O365 Groups using Graph on Classic SP Page.js

(async function() {

function getAccessToken(resource) {
    return new Promise( async (resolve, reject) => {

        var body = {
            "resource": resource || "https://graph.microsoft.com"
        };
        const url = `${_spPageContextInfo.webAbsoluteUrl}/_api/SP.OAuth.Token/Acquire`;
        const response = await fetch(url, {
            "method": "POST",
            "headers": {
                "X-RequestDigest": _spPageContextInfo.formDigestValue,
                "Accept": "application/json;odata=nometadata",
                "Content-Type": "application/json;odata=nometadata"
            },
            "body": JSON.stringify(body)
        });
        const data = await response.json();

        console.info(data);
        var accessToken = data.access_token;
        resolve(accessToken);
                
    });
}
function getGroups(accessToken) {
    return new Promise( async (resolve, reject) => {

        const url = `https://graph.microsoft.com/v1.0/groups`;
        const response = await fetch(url, {
            "method": "GET",
            "headers": {
                "Accept": "application/json",
                "Authorization": `Bearer ${accessToken}`,
            },
        });
        const data = await response.json();

        console.info(data);
        resolve(data);
                
    });
}

console.clear();

const accessToken = await getAccessToken("https://graph.microsoft.com");
console.info("accessToken", accessToken);

const groups = await getGroups(accessToken);
console.info("groups", groups.value);

})();