[Risolto] Adding a custom language (papiamentu), I do not know the Default locale for this language

Background of the issue:
I am developing a site and trying to add a custom language (Papiamentu) using WPML. I am following the documentation provided at https://wpml.org/documentation/getting-started-guide/language-setup/editing-wpmls-languages-table/#adding-a-custom-language-in-the-setup-wizard.

Symptoms:
I do not know the Default locale for the Papiamentu language.

Questions:
What is the Default locale for the Papiamentu language?