Backup Functions in PgAdmin 4 Version 1.6

How to backup all functions in pgadmin 4 version 1.6?
After executing the below query the backup functions stored in which place?
And how to find it?
How to know all information is backed up with what’s being done?

SELECT pg_get_functiondef(f.oid) || E';n'
FROM pg_proc f
   JOIN pg_namespace n ON f.pronamespace = n.oid
WHERE n.nspname = 'schemaname';