GCP - Can't create a tpu on europe-west1
According to "TPU types and zones" TPUs are only available in a very limited set of regions, namely:


Europe, Middle East and Africa


europe-west4-a (Eemshaven, Netherlands)

Americas


us-central1-a, b, c and f (Council Bluffs, Iowa, USA)

Asia-Pacific


asia-east1-c (Changhua County, Taiwan)



Note: not every SKU is available in each region, so double check the above page when planning your deployments.

In addition to specifying a valid zone, you will need to make sure the TPU API is enabled, and your account has the relevant IAM permissions: Cloud TPU\TPU Admin.

At the moment TPUs are predominantly designed for centralised data processing rather than close-to-edge processing. Hence the somewhat limited number of locations TPUs are available within.