I can’t buy i cloud with redeem card?

Check -> Go to -> Settings -> your name -> iCloud -> if you see 50 GB (or 200 GB or 2 TB) then you have an iCloud subscription.

If you have an iCloud subscription, you will receive a monthly bill from Apple, check your email box.

You pay monthly for iCloud storage.

• If you have upgraded iCloud storage, it would take about 1 to 3 business days in order to process.
• Once your request for iCloud+ has been activated, you should receive an invoice in your email box.

You may need to have a payment method on file, even if the app you want to download is free. 

Check which payment method you have on file 

See the following Apple articles:

Payment methods you can use with your Apple ID

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

Add money to your Apple ID balance

Add money to your Apple ID balance – Apple Support (UK)

• If you don't want to use a bank card, you can use Apple ID balance as your payment method.

I have a 10$ in my app store and i cant buy a 2 TP which is 9.99$ why?

Because you can't just use iCloud+ storage just for one month.

iCloud+ subscription is an 'ongoing' event.

The subscription runs as long as you don't downgrade.

You cannot deactivate/pause the subscription for 1 month, but you can downgrade to free (5 GB).

See ->  Downgrade or cancel your iCloud+ plan

Downgrade or cancel your iCloud+ plan - Apple Support (PH)

You can add that 10$ to your Apple ID balance.

See also: iCloud+ plans and pricing

iCloud+ plans and pricing - Apple Support

The amount you have in your Apple ID balance should be more than that.