hi,
mariadb installed but You chose SQLite as database why
how can i fix this problem?
written on the screen
"Performance warning
You chose SQLite as database.
SQLite should only be used for minimal and development instances. For production we recommend a different database backend.
If you use clients for file syncing, the use of SQLite is highly discouraged."
See the Admin Manual: Converting database type — Nextcloud latest Administration Manual latest documentation
A short additional information. You have accidentally selected SQLite instead of MariaDB. You can try the suggested migration from @jtr. Alternatively, you can select MariaDB at this point for a possible new installation. Please note that a MariaDB with the required access data must be available for this.