Javascript code to create a site collection app catalog from browser console

creatsitecollectionappcatalog.js

// POST request Call
function RestRequest(url, params) {
    var req = new XMLHttpRequest();
    return new Promise(function(resolve, reject) {
        req.onreadystatechange = function() {
            if (req.readyState != 4) // Loaded
                return;
            if (req.status >= 200 && req.status < 300) {
                resolve(req);
            } else {
                reject({
                    status: req.status,
                    statusText: req.statusText
                });
            }
        };
        var webBasedUrl = url;
        req.open("POST", webBasedUrl, true);
        req.setRequestHeader("Content-Type", "application/xml");
        req.setRequestHeader("x-requestdigest", _spPageContextInfo.formDigestValue);
        req.send(params ? params : void 0);
    });
}

function createsiteappcatalog(adminurl,siteurl){
    RestRequest(adminurl+'/_vti_bin/client.svc/ProcessQuery', '<Request AddExpandoFieldTypeSuffix="true" SchemaVersion="15.0.0.0" LibraryVersion="16.0.0.0" ApplicationName="SharePoint Designs Application" xmlns="http://schemas.microsoft.com/sharepoint/clientquery/2009"><Actions><ObjectPath Id="38" ObjectPathId="37" /><ObjectPath Id="40" ObjectPathId="39" /><ObjectPath Id="42" ObjectPathId="41" /><ObjectPath Id="44" ObjectPathId="43" /><ObjectPath Id="46" ObjectPathId="45" /><ObjectPath Id="48" ObjectPathId="47" /></Actions><ObjectPaths><Constructor Id="37" TypeId="{268004ae-ef6b-4e9b-8425-127220d84719}" /><Method Id="39" ParentId="37" Name="GetSiteByUrl"><Parameters><Parameter Type="String">'+siteurl+'</Parameter></Parameters></Method><Property Id="41" ParentId="39" Name="RootWeb" /><Property Id="43" ParentId="41" Name="TenantAppCatalog" /><Property Id="45" ParentId="43" Name="SiteCollectionAppCatalogsSites" /><Method Id="47" ParentId="45" Name="Add"><Parameters><Parameter Type="String">'+siteurl+'</Parameter></Parameters></Method></ObjectPaths></Request>').then(function(resp) {
        console.log(resp);
    });
}