To use any of the above modules, you need to have a GitHub account. If you do not have one yet, you can create one at GitHub.com. Then you need to sign in with your GitHub account to Gitter at Gitter.im
To connect your Gitter account to Integromat, follow the general instructions for Connecting to services. After you click the Continue button, Integromat will redirect you to the Gitter website where you will be prompted to grant Integromat access to your account:
Here, allow access by clicking the Allow button. Afterwards, you will be redirected back to the Integromat administration page. Now, you can continue creating your scenario.