How to recover data from docker export file on synology

[spaminbox]

Could someone please advise me on how to recover database from synology docker export file?

I use Teslamate on my synology NAS using docker. For some reason i couldn't login to teslamate. I thought to completly reinstall docker. Before removing the application i took a backup of the database container using the export function on docker.
After the reinstallation i can login on teslamate so that problem was solved. I thought i could just import the database again but no! It's not that simple. It doesn't recognize the database. Is someone willing to help me back in business?