I cant pay from the app store

I have 4$ in my apple store but when i pay somthing like in 1$ he say

You can check your Apple ID balance, see -> Check your Apple ID balance

Check your Apple ID balance – Apple Support (UK)

If you get a message -> Your purchase could not be completed, you need to update your payment method or add a new one. 

• if you want to use your Apple ID balance, you need to set your Apple ID balance as your default payment.

See also -> Payment methods you can use with your Apple ID

Payment methods you can use with your Apple ID – Apple Support (UK)

If you update your payment method or add funds to your Apple ID balance, It would take about 1 to 3 business days in order to process.

If you're still unable to update your payment method, Contact Apple Support.

Click here for more support and assistance.

HiAka,

You may see various forms of a "Your purchase could not be completed" message. Some may show old URLs (such as the one ending in "/ww/") which will redirect to the current one which leads you to a page to select your country but then provides little additional guidance. Since it says to contact iTunes Support, do this:

1. Click on this link --> Choose your country or region - Official Apple Support

2. Select your country

3. Select: Billing & Subscriptions

4. Select: Subscriptions & Purchases

5. Select: Update payment method

6. Select a chat session or a phone call.