post https://id.ap-northeast-1.cloud.japancv.co.jp/api/v1/identities//portrait/register
Create a self-registration hash for the identity owner to upload the portrait by themselves. The link with this hash can only be used once. The old hash will expire if a new link is issued to the same identity.
To compose the full url, attach the hash in the following pattern: https://cloud.japancv.co.jp/idp/{$region}/one-time-update/{$hash}
Example: https://cloud.japancv.co.jp/idp/ap-northeast-1/one-time-update/3WL34XU4FEt3eafWfGPt7uvwHKASTBQJ
For the list of regions, refer to the list of servers.