Esperanto Postage Due - Country Origin?

Translation is:

Language International
Post-paid (or stamped) on the other hand

So, I believe it is a postage due.
Would anyone know the origin or year?
There is a symbol at the top of the star. Turkey?
Thanks!

This may help in some way at least it is worth a look.

https://alphabetilately.org/Esperanto/rels.html

Hobsun

It's just a cinderella, a poster stamp used to advertise Esperanto. The label at the bottom, AFRANKITA ALIFLANKE (stamped on the other side), would be used to inform the postal authorities that the actual postage stamp is on the other side of the card or envelope. I've never seen a label of that sort before, but I've seen (and own) numerous postcards with something similar written or rubber-stamped on them. Such an indicator is usually written in the language of the country of origin, and very often is nothing more than an arrow. For example, I have an Esperanto postcard from Austria with "MARKE UMSEITIG" ("stamp on the reverse" in German) rubber-stamped on it. It was common to put such an indicator on the address side of a picture postcard, so that the stamp could be affixed to the picture side.

The lettering suggests sometime between 1900 and 1930 to me, but beyond that I can't really help with the date or country of origin. I don't think it has anything to do with Turkey, though.

Esperanto; It was an attempt to make an international language. It is still relevant although English has just become that, more or less. It was started in about the 1880's. I think that is a poster stamp, collectible. I would place it in the BOB Italian section of your stamp album.

Around 70% of the basic Esperanto vocabulary derives from the Romance languages, with the result that it looks and sounds somewhat similar to Italian or Spanish, but Esperanto has nothing to do with Italy specifically. Its inventor, L.L. Zamenhof, lived in the Russian Empire, in what is now Poland.