401 Malformed key

The key was present but is not in the expected format, so it was rejected without a lookup.

Keys look like this:

ig_pk_XXXXXXXXXXXXXXXX_YYYYYYYYYYYY    publishable, 35 characters
ig_sk_XXXXXXXXXXXXXXXX_YYYYYYYYYYYY    secret, 35 characters

Common causes

Truncation. A key pasted into a field with a length limit, or split across lines in a config file. Check the length is exactly 35 characters.

A trailing space or newline. Especially when read from a file or an environment variable.

URL encoding applied twice. If you are building the URL by hand and the key already appears encoded, encoding it again corrupts it.

The wrong value entirely. A project id (prj_…) or a Stripe key (pk_live_…) is not an instantgeo key.

Copy the key again from your dashboard.