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';
This is not backing up your functions, it is just selecting the text of them.  You could copy the result from pgAdmin and save it to a text file manually if you want.

If you take a full backup of your database the functions will be backed up along with the data.