Hey @Garima Singh
thank you for your reply.
The way you described it did not work for me. I could only restore an old database, but not the current database on my Mac.
I made a backup of the relevant Vault database (xxx_vault-20_items.enpassbackup). Then I transferred this backup file to my partner's iPhone. Then I uploaded the backup to Enpass on my partner's iPhone.
But the problem is that my partner's Vault does not sync with Enpass on my Mac.
I installed Enpass on my partner's iPhone via family share. My partner also has an iCloud family share, but still syncing is not possible.