Hi @noor_mohammed! If you want to install the ODK-X server locally, here are the details:
https://docs.odk-x.org/sync-endpoint-manual-setup/#sync-endpoint-manual-setup
If you are setting up the ODK-X server locally, you do need an underlying database:
https://docs.odk-x.org/sync-endpoint-manual-setup/#custom-database
which one is going to depend on your particular setup, we ran into problems in the past with some setups and database size but PostgreSQL has worked well and there’s a default setup on github GitHub - odk-x/sync-endpoint-default-setup: A cloud server to host data and application files, and to support bi-directional data synchronization across disconnected mobile devices.
There aren’t specific recommended specs (it will depend on the needs for your case), but you can search the Forum for discussion/examples like this: ODK Sync endpoint -- Where is data stored on the server? - #6 by Jeff_Beorse