unable to see offline_access Scope Missing from Token Response

I’m using MSAL.js in my Outlook Add-in to authenticate users and obtain tokens. My configuration includes the offline_access scope, but it appears to be missing from the token response. This prevents me from getting a refresh token. Here is my current configuration and token request code:

const msalConfig = {
    auth: {
        clientId: "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX",
        authority: "https://login.microsoftonline.com/common",
        redirectUri: _redirectUri,
    },
    cache: {
        cacheLocation: "localStorage", // This configures where your cache will be stored
        storeAuthStateInCookie: true,  // Set this to "true" if you are having issues on IE11 or Edge
    },
    system: {
        loggerOptions: {
            loggerCallback: (level, message, containsPii) => {
                if (containsPii) {
                    return;
                }
                switch (level) {
                    case msal.LogLevel.Error:
                        console.error(message);
                        return;
                    case msal.LogLevel.Info:
                        console.info(message);
                        return;
                    case msal.LogLevel.Verbose:
                        console.debug(message);
                        return;
                    case msal.LogLevel.Warning:
                        console.warn(message);
                        return;
                }
            },
        },
    },
};

const loginRequest = {
    scopes: ["User.Read", "Mail.ReadWrite", "offline_access"],
    prompt: "select_account",
};

const tokenRequest = {
    scopes: ["User.Read", "Mail.ReadWrite", "offline_access"],
    prompt: "select_account",
    forceRefresh: true,
};

function getTokenPopup(request, myMSALObj, username) {
    request.account = myMSALObj.getAccountByUsername(username);

    return myMSALObj.acquireTokenSilent(request).catch((error) => {
        console.warn("Silent token acquisition fails. Acquiring token using popup");
        if (error instanceof msal.InteractionRequiredAuthError) {
            return myMSALObj.acquireTokenPopup(request)
                .then((tokenResponse) => {
                    // Log the token response to see what's included
                    console.log("Popup token acquisition successful:", tokenResponse);

                    // Check if tokenResponse includes the necessary tokens
                    const { accessToken, idToken, expiresOn, scopes, account } = tokenResponse;

                    console.log("Access Token:", accessToken);
                    console.log("ID Token:", idToken);
                    console.log("Expires On:", expiresOn);
                    console.log("Scopes:", scopes);
                    console.log("Account:", account);

                    // Check if offline_access scope is included
                    if (scopes.includes("offline_access")) {
                        console.log("Refresh token should be available.");
                    } else {
                        console.log("Refresh token is not available. Ensure offline_access scope is requested.");
                    }

                    // Return the token response for further processing
                    return tokenResponse;
                })
                .catch((error) => {
                    console.error("Popup token acquisition failed:", error);
                });
        } else {
            console.warn("Non-interaction error occurred:", error);
        }
    });
}

I have set the permission on Azure AD as well.