I want to rewrite all this link:

https://example.com/myapp/?randomparam1=true&randomparam2=false
https://example.com/myapp/randomdir/

to:

https://example.com/wp-content/themes/mytheme-child/webapp/myapp/?randomparam1=true&randomparam2=false
https://example.com/wp-content/themes/mytheme-child/webapp/myapp/randomdir/

and this is my code

add_action('init', function(){
    add_rewrite_rule( 'myapp/(.*)','wp-content/themes/mytheme-child/webapp/myapp/$matches[1]', 'top' );
    //add_rewrite_rule( 'myapp/\?(.*)', 'wp-content/themes/mytheme-child/webapp/myapp/index.php?$matches[1]', 'top' );
});

But it doesnt work. Can you please tell how to fix this?