how i can change my region without credit card

You may use a debit card instead of a credit card --> Based on your country of residence and country you have selected under your Apple ID --> Payment methods that you can use with your Apple ID - Apple ...

If you can't choose None as a payment method only if...

1. If you have an unpaid balance or payment due
2. If you have a subscription that automatically renews
3. If you're using the iTunes Store or App Store for the first time
4. If you are not in the country or region you’re creating an Apple ID for
5. If you changed your country or region
6. If you're a part of Family Sharing

If you can't make purchases or update apps, including free apps, you need to update your payment method or add a new one. If you already verified that a payment method is available in your country or region and you're still having trouble, learn more.