Update template

Update one variant's components. Name, language and category cannot change after creation.

Meta stores one template per name + language, so a name identifies a family of variants, each with its own Meta id. Pass language to address one variant. Without it, a name with a single variant resolves to that variant; a name with several returns 409 ambiguous_template with details.languages. A bare language (es) matches a single regional variant (es_ES); if the family has several regional variants for it, that is also a 409. A full code (es_ES) must match exactly. Variants in PENDING_DELETION are not part of the family.

Meta only allows editing templates in APPROVED, REJECTED or PAUSED state; an approved template can be edited once per 24 hours and up to 10 times per 30 days. A successful update sends the variant back to Meta for review, so the status returned here is normally PENDING. The final outcome arrives on the whatsapp.template.status_updated webhook (which carries the variant's templateId and language). A variant already in PENDING cannot be edited again until Meta finishes reviewing it.