Add the subdomain for your ApplicantStack account.

For example, if you sign in at "acme.applicantstack.com", add acme below.

Do not add the full "acme.applicantstack.com".

Log in to ApplicantStack as an admin for your organization, and click on Update Settings in the right-side panel.

Near the bottom of the page, you'll see a section called API Settings. Copy and add the API Access Token to Merge Link.