As far as I can tell, the answer is “you can’t”. As far as I can tell, PCloud does not have a service set up to provide this functionality. (Did you ask them?)
For the purpose indicated, the sharing service must be available to each client. PCloud offers only file sharing, not database sharing.
Any web hosting service these days will include a database service. Still, some will restrict db access to “local” so you can only access the db by scripts running on the web host. Look for hosting which allows external access and provides proper SSL/TLS security. Make sure you get sufficient space for your data and the provision for offline backups.
Running a database service in the cloud is not trivial, due to networking, security and legal challenges alike. This article attempts to shed light on the matter.