Personally I would make an sql / mysql server for data persistence.
Use the tools that are designed for the task.
You can pass in the information through a custom rest API.
OFC you would have to host the server yourself. Unreal does not have any built in data base functionality out of the box (data tables are not equivalent to relational databases).
You could use Epic Online Services for this too (it does have a persistence option) but it might be more costly in the long term.
https://dev.epicgames.com/docs/game-services/player-data-storage