export specific secret value as an environment variable

Hmm let me make sure I understand the issue correctly:

When you run op item get --cache --format=json [gcp location], the [gcp location] part is, in fact, the name of your item, is this correct?

The issue here may be that this name contains the "/" character, which is not valid in secret references.

So, to reiterate, in order to create a valid secret reference, you would need:
1. the vault name or ID (Engineering, from the json output I see you provided above)
2. the item name or ID - if your item name contains unsupported characters, you can use the item ID, that you replaced above with "bla"
3. the field name or ID - secret, in your case

So I think a valid secret reference should be op://Engineering/<your-item-id>/secret.
Can you please let us know what does op read, given the above as an argument, return?

Thank you!

Best,
Horia