I have the same issue as.
Can't login with admin:admin
Restarting of the docker container after first initial startup did not help as well. I also waited +5 min. before I opened the website and tried to login
2022-10-04 21:05:01.998 CEST [784] ERROR: relation "api_user" does not exist at character 746
2022-10-04 21:05:01.998 CEST [784] STATEMENT: SELECT "api_user"."id", "api_user"."password", "api_user"."last_login", "api_user"."is_superuser", "api_user"."username", "api_user"."first_name", "api_user"."last_name", "api_user"."email", "api_user"."is_staff", "api_user"."is_active", "api_user"."date_joined", "api_user"."scan_directory", "api_user"."confidence", "api_user"."confidence_person", "api_user"."image_scale", "api_user"."semantic_search_topk", "api_user"."avatar", "api_user"."transcode_videos", "api_user"."nextcloud_server_address", "api_user"."nextcloud_username", "api_user"."nextcloud_app_password", "api_user"."nextcloud_scan_directory", "api_user"."favorite_min_rating", "api_user"."save_metadata_to_disk", "api_user"."datetime_rules", "api_user"."default_timezone" FROM "api_user" WHERE "api_user"."username" = 'admin' LIMIT 21
