Click Payment options and then Stripe Test. InviteMember bot will send you a link which you should open in your browser:
It will open a webpage on Stripe website:
If you are adding Stripe in Test mode, you can skip the form and click Skip this account form.
You should see a confirmation now:
As soon as we get your account info, InviteMember bot will send you a confirmation as well:
Done! Now you can accept test payments without a real credit/debit card.