Insert Link from feed item to click event

I’d like to set up a link in my page in the following format:

<button ion-button="" large="" color="primary" (click)="launch('url')">Launch Maps</button>

I’m pulling page content from a Wordpress REST API feed. Items are in this format: selectedItem.field_name

I’d like to insert the feed item “selectedItem.maps_url” into the ‘url’ of the above button but when I insert the field name it doesn’t render.
<button ion-button large color=“primary” (click)=“launch(‘selectedItem.maps_url’)”>Launch Maps

In fact, it doesn’t render inside simple links either, e.g.
<a href="selectedItem.maps_url">Link</a>.
Edit: Figured out that wrapping href as [href] solves this issue. Still need to figure out first part though.

But does outside, so I know it’s being fed to the page. So, I’m guessing it’s either not possible (pls no!) or I’m missing something in formatting.

Any help is much appreciated.