Safety & facility warnings - Some indexes are missing in the database

Due to the fact that adding indexes to large tables can take some time, they were not created automatically. By running “occ db:add-missing-indices” the missing indices can be added manually while the instance is still running. After the indexes have been added, queries to the tables are usually faster.
Missing index “fs_mtime” in the table “oc_filecache”.
What can I do in this case?

Try this: