Dynamic remote register with either window object/promise RsBuild & Module Federation 2.0

[annfredin]

tools: {
rspack: (config, { appendPlugins }) => {
appendPlugins([
new ModuleFederationPlugin({
name: 'host',
remotes: {
remote1: 'remote1@http://localhost:3001/mf-manifest.json',
},
shared: ['react', 'react-dom'],
}),
]);
},
},

The above code is working fine, but when i change as below not working.

window object
remotes: {
remote1: 'remote1@[remote_apps.app1]/mf-manifest.json',
},
promise
remotes: [
{
remote1: {
external: "Promise.resolve(window.remote_apps.app1)",
}]
If I use init method to init & register
init({
name: 'host',
remotes: [
{
name: 'app1',
entry: 'http://localhost:3001/mf-manifest.json',
},
],
});
Then sync import ==> import {button } from "app1/button" not working

can someone suggest me the better way for dynamic register