Taxpayers can avail services of an ASP (Application Service Provider) or GSP (GST Suvidha Provider) to perform GST compliance-related activities such as filing GST Returns. They need to allow access to APIs for ASP/GSPs.
It is a security feature that prevents any unauthorized access to your information. Taxpayers need to first activate API session on GST Portal. They can define period for which their session should remain active either minimum of 6 hours or maximum of 30 days.
Taxpayers can deactivate API Access by choosing option “No” under the “Enable API Request” field.
Read step-wise process - GST Portal : Manage API Access