Hey, ​@sohanasserrr!

It depends on what stage are you.
If you’re using the Pro trial, you’ll need to contact the support team to change it, but if you’re on the free plan, follow these steps:

1. Go to settings
2. Click on billing
3. Select and activate the Marketing Automation

After that, you’ll need to insert the information with bank card’s number, etc, and you’re good to go.

Now, if you’re paying more than $15, and you want to decrease your invoice, you’ll need to unsubscribe some contacts (the max. is 500 contacts).

Let me know if this helps