Hello and welcome to the forum :)
In most r3 apps, automating tasks like this via API calls would be simple. But the PW Safe uses end to end encryption. This means that the server does not have access to the encryption keys required to handle encrypted data - this is done 100% on the user´s end (ie. on the frontend).
In theory, it would be possible for a server to only encrypt for others, as this just requires the public keys for each user the entry would be encrypted for. But we have not implemented this option on the backend yet.
E2EE is a very good standard to strive for, but it does have downsides, such as backend systems being limited on what they can do. A more basic, system wide encryption would enable this use case, but alas.