`programme_not_set_up`

Status 409. This store has no programme set up yet.

What it means

The store has no loyalty programme yet: no currency and no earning rate, so there is nothing to change. Nothing was changed.

Set the programme up once in the Matrix Rewards app, where the set-up guide takes a minute. After that, send the change again.

Not as it is. Change what the answer points to, then send the request.

Every code, and the shape of an error answer: Errors.