Change the payload in a test

I am testing my login endpoint in Insomnia Designer with the integrated test tool.

A successful login test looks like this with the selected login request:

const response = await insomnia.send();
const body = JSON.parse(response.data);

expect(response.status).to.equal(200);
expect(body).to.have.property("token");

Now I want to change the test with invalid credentials in order to check for a response.status 401.

How can I change this in Insomnia Designer programmatically?