sql server - What TSQL gives rights to create functions on a schema -

i have program runs following sql:

create function [foo\bar].something ( 

the sql looks fine, error

the specified schema name "foo\bar" either not exist or not have permission use it. 

what sql can run on database schema access create function? think want keep default schema dbo , have access other [foo\bar] schema.

the sql server books online states in create function topic (https://msdn.microsoft.com/en-us/library/ms186755.aspx):

requires create function permission in database , alter permission on schema in function being created