I do not see my credits

Hello.

What kind of credits do you mean by credits?
There is no need to worry about the free tier of your AWS account as it will be applied automatically.
You can check the usage status of the free tier by following the steps in the document below.
https://docs.aws.amazon.com/awsaccountbilling/latest/aboutv2/tracking-free-tier-usage.html

To see the details in your Billing and Cost Management console, Sign in to the AWS Management Console and open the AWS Billing console at https://console.aws.amazon.com/billing/

• In the navigation pane, choose Bills.
• To display the discount, select the arrow next to Total Discounts, under Credits, Total Discounts and Tax Invoices.

To view any credits in your account, follow these steps:

1. Open Cost Explorer
2. Open Reports
3. Use the existing Monthly cost by service
4. In the right menu options, select Dimension = Cost Category.
5. In the right menu options, select Charge Type = Credit

This is going to show you all credits to your account.