Hi @Marvin Dacuag , if this works for your scenario you may be able to add a custom language.
You can also add languages that Microsoft currently does not provide translations for. You'll need to provide the translations for all the strings in the user flow. Language and locale codes are limited to those in the ISO 639-1 standard. The locale code format should be "ISO_639-1_code"-"CountryCode", for example en-GB. For more information on locale ID formats, please refer to https://learn.microsoft.com/openspecs/office_standards/ms-oe376/6c085406-a698-4e12-9d4d-c3b0ee3dbc4a
Please follow the linked document for more details. Please let me know if you have any questions!
If this answer helped you please mark it as "Verified" so other users may reference it.
Thank you,
James