how to ensure multiple systems generate the next unique value in a single sequence when all systmes run in paralell

Question

I'm a novice / amateur so please forgive the lack of technical language. I have a scenario where I have multiple devices running simultaneously, each need to generate the next available unique ID sequentially in a shared sequence and validate that the values being set is unique in the shared database. The data base will be cloud based and transactions could be sent directly to it over wifi / 4g but latency could/will prevent the individual devices from Being able to validate uniqueness and return the next sequence without getting mixed up. My current proposed solution is to have an on premise server where the devices will send the data for validation and then this server will send the data to the cloud DB but part of the idea is that the devices should be able to easily move locations. Does anyone have any advice on how I could handle these simultaneous validations?