Hi,
The templates are editable via the MapPress settings screen. They’re saved in your theme directory, and the originals are in the /templates directory of the plugin. There’s general information about this in the MapPress documentation.
I think you are asking to display a field only if non-empty. For that, you would need some javascript in the template. You can do a simple if statement by using three braces:
{{{ (poi.props.annonce_surface) ? poi.props.annonce_surface : 'empty'}}}
Or, make a conditional block using ‘<#’ and ‘#>’ around the JavaScript parts:
<# if (poi.props.annonce_surafce) { #>
<i class=””fal” aria-hidden=””true””></i> {{poi.props.annonce_surface}} m²
<# } #>