How to check if the SYSTEM_VERSIONING for a table is ON?
You could query sys.tables

ALTER TABLE EmpSalary SET (SYSTEM_VERSIONING = On );
select name, temporal_type, temporal_type_desc from sys.tables where name = 'EmpSalary'

| name      | temporal_type | temporal_type_desc              |
|-----------|---------------|---------------------------------|
| EmpSalary | 2             | SYSTEM_VERSIONED_TEMPORAL_TABLE |




ALTER TABLE EmpSalary SET (SYSTEM_VERSIONING = OFF );
select name, temporal_type, temporal_type_desc from sys.tables where name = 'EmpSalary'

| name      | temporal_type | temporal_type_desc |
|-----------|---------------|--------------------|
| EmpSalary | 0             | NON_TEMPORAL_TABLE |