Database files on mysql
Traccar can't do it for you, but there might be some tools out there to migrate database.
Which tool you can recommend
and a question outside of the topic
Can I limit somehow the data storage period to, for example, 90 days
I can't recommend any tool.
You can limit history. Read documentation.
I can not find such information in the documentation.
And if you can do it. And what cost?
Send an email to support address if you need help with migration.
As for history, relevant documentation is here:
Is it possible to transfer all data from the database in files (database.mv and database.trace) to the mysql database. I really want all data to be transferred. The files weigh a total of 361 MB.