How to add custom action in react-admin

My way of solving this:

1. create custom button:

    import Button from '@material-ui/core/Button';
    import { TopToolbar } from 'react-admin';
   
    const PostShowActions = ({ basePath, data, resource }) => (
    <TopToolbar>
        {/* Add your custom actions */}
        <Button color="primary" onClick={customAction}>Custom Action</Button>
    </TopToolbar>
    );
   
    export const PostList = (props) => (
    <List actions={<PostShowActions />} {...props}>
        ...
    </List
    );
   

2. navigate it to the API: I implemented customAction like this:

   const genarte = () => {
       const httpClient = fetchUtils.fetchJson;
       const apiUrl = "your API";
       httpClient(`${apiUrl}`,{method: "POST"}).then(({ json }) => ({
                   data: json,
                 })
   
       ); };
   

I know it doesnt navigate the page to external link only make a http request, but now for my need its ok.

if you have any comment or idea how to navigate the page to extranl link I would be happy