To force a scan after a manual file transfer, for example, can be done as follows:
sudo -u [USER] php occ files:scan --all
for example:
sudo -u john php occ files:scan --all
Usage: files:scan [-p|--path="..."] [-q|--quiet] [-v|vv|vvv --verbose] [--all] [user_id1] ... [user_idN] Arguments: user_id will rescan all files of the given user(s) Options: --path limit rescan to the user/path given --all will rescan all files of all known users --quiet suppress any output --verbose files and directories being processed are shown additionally during scanning --unscanned scan only previously unscanned files
Source: https://docs.nextcloud.com/server/15/admin_manual/configuration_server/occ_command.html