Schema name can't replace in snippet (schema.json)

{ "message": "type \"rule_type\" already exists", "severity": "ERROR", "code": "42710", "where": "SQL statement \"create type rule_type AS ENUM ('MARC_BIB', 'MARC_HOLDING')\"
PL/pgSQL function inline_code_block line 1 at SQL statement", "file": "typecmds.c", "line": "1191", "routine": "DefineEnum" }" 

{
  "run": "after",
  "snippet": "DO $$ BEGIN IF NOT EXISTS (SELECT 1 FROM pg_type t JOIN pg_enum e ON t.oid = e.enumtypid JOIN pg_catalog.pg_namespace n ON n.oid = t.typnamespace WHERE t.typname = 'rule_type' AND n.nspname = '${myuniversity}_${mymodule}') THEN create type rule_type AS ENUM ('MARC_BIB', 'MARC_HOLDING'); END IF; END $$; ALTER TABLE mapping_rules ADD COLUMN IF NOT EXISTS record_type rule_type NOT NULL DEFAULT 'MARC_BIB';",
  "fromModuleVersion": "mod-source-record-manager-3.2.0"
}

DO $$
BEGIN
  IF NOT EXISTS (SELECT 1 FROM pg_type t
                 JOIN pg_enum e ON t.oid = e.enumtypid
                 JOIN pg_catalog.pg_namespace n ON n.oid = t.typnamespace
                 WHERE t.typname = 'rule_type' AND n.nspname = '${myuniversity}_${mymodule}')
  THEN create type rule_type AS ENUM ('MARC_BIB', 'MARC_HOLDING');
  END IF;
END $$;
ALTER TABLE mapping_rules
  ADD COLUMN IF NOT EXISTS record_type rule_type NOT NULL DEFAULT 'MARC_BIB';

trying to execute: {}           DO $$ BEGIN IF NOT EXISTS (SELECT 1 FROM pg_type t JOIN pg_enum e ON t.oid = e.enumtypid JOIN pg_catalog.pg_namespace n ON n.oid = t.typnamespace WHERE t.typname = 'rule_type' AND n.nspname = '${myuniversity}_${mymodule}') THEN create type rule_type AS ENUM ('MARC_BIB', 'MARC_HOLDING'); END IF; END $$; ALTER TABLE mapping_rules ADD COLUMN IF NOT EXISTS record_type rule_type NOT NULL DEFAULT 'MARC_BIB';"