[Решено] Only two translation engines

Background of the issue:
I am trying to select Deepl as the translation engine for my WordPress site using WPML, but I can only choose between Microsoft and PTC. I found a related thread here: https://wpml.org/forums/topic/no-deepl-in-my-translation-engines/ and was advised to re-save the translation engine setting in my account.

Symptoms:
I am unable to select Deepl as a translation engine; only Microsoft and PTC are available.

Questions:
Why can't I select Deepl as a translation engine?