how to print value of a taxonomy field to headline with node.html.twig? field_test1 is a taxonomy field like fields_tags.

{{ content.field_test1 }} prints the title and the value (not in teaser - why not?).
I only want the value and want to print it in the header of the node before {{ label }}.

{{ content.field_test1.value }} or {{ node.field_test1.value }} don't work.

{{ node.field_example.value }} seems to work only for "usual" fields, but not for taxonomy fields.

How to do that?

(I've read the book of Chaz Chumley, but found no solution. I've got an answer of 4k4 in another thread, but I didn't understand. Therefore I've clarified my question here.)
That's because a taxonomy field has no values. It contains entities, which are the referenced terms. You get the first term with .entity and then you can get the values inside of the term, for example if the term would have a field_test2:
{{ node.field_test1.entity.field_test2.value }}

Or simply the term label (no .value needed for this):
{{ node.field_test1.entity.label }}

If you need translation use the |translation filter of the module Twig Tweak.