This function sends a POST request to the API with the specified parameters and text.
Deprecated
post_request() is a low level building block that was never meant to be
part of the public interface. It is deprecated as of textrar 0.9.0 and
will be removed in a future release. Use textra() instead. If you rely
on it to reach an endpoint that textra() does not cover, please open an
issue at https://github.com/matutosi/textrar/issues so that a supported
way of doing so can be provided.