Recursively fetch all sites from site collection

Hi,

Could you please provide a code sample.

I have checked for the below:

function checkRootSite() {
    var siteUrl = _spPageContextInfo.siteServerRelativeUrl;
    this.webUrl = _spPageContextInfo.webServerRelativeUrl;
    this.isRootWeb = siteUrl == webUrl;
    
if (isRootWeb) {
        this.rootSite = clientContext.get_site().get_rootWeb();
        clientContext.load(this.rootSite);
        clientContext.executeQueryAsync(Function.createDelegate(this, this.onRootWebLoaded), Function.createDelegate(this, this.onQueryFailed));
    }
}

But how does the recursive operation work for the users with Read only access?

Thanks