Variable in dict keys

[SuicidalToaster]

I've been pondering one problem for some time and can't think of anything. I am required to list values from file with KV structure by passing variable to dict key but I couldn't do it . Why my template isn't working? Is it possible to make it work? Is it wrong approach?

upstream main-srv-{{ env }} {
    least_conn;

{% for host in groups[{{ my_var }}] %}
    server {{ hostvars[host]['ansible_host'] }}:80;
{% endfor %}
}

Full trace

The full traceback is:
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/ansible/template/__init__.py", line 975, in do_template
    t = myenv.from_string(data)
        ^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/jinja2/environment.py", line 1105, in from_string
    return cls.from_code(self, self.compile(source), gs, None)
                               ^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3/dist-packages/jinja2/environment.py", line 768, in compile
    self.handle_exception(source=source_hint)
  File "/usr/lib/python3/dist-packages/jinja2/environment.py", line 936, in handle_exception
    raise rewrite_traceback_stack(source=source)
  File "<unknown>", line 4, in template
jinja2.exceptions.TemplateSyntaxError: expected token ':', got '}'

Thanks in advance

[kwist-sgr]

and if so?

upstream main-srv-{{ env }} {
    least_conn;

{% for host in groups[my_var] %}
    server {{ hostvars[host]['ansible_host'] }}:80;
{% endfor %}
}

[SuicidalToaster]

Oh God, it was that simple
Thanks a lot! I really should get to know jinja better