To Check Sales/Purchase Rgister with Item and HSN Code and GST detail, Please follow below steps :
Step 1 : Go to the Display menu and choose GST Reports.
Step 2 : Select GST Register and then choose either Sales Register or Purchase Register.
Step 3 : Within the Register, pick the option to view the report based on Bill-Wise, item-Wise, HSN Code-Wise.
Step 4 : Execute the report and use the Custom Column option to create a new format. Add a new column for the HSN code.
Step 5 : Now,Generate the report again using the format you just created. This will display the Sales/Purchase Register with Item and HSN Code details.