Hi there! You could set up a default link with your English content. In this way, you could use “x-default” attribute for specifying a page, that does not have any region or language associate with it. It could potentially be your English version content. For example,
link rel=“alternate” href=“http://example.com/” hreflang=“x-default”
If you are interested in more details about how to set up hreflang tag correctly, you may look at the post: https://geotargetly.com/hreflang-seo-guide-for-multilingual-regional-websites
Hope it helps!