@Marco Maddiona The most likely reason that the pricing tier dropdown is not listed is because Bing news service is not registered with your subscription. Could you please navigate to the following path from Azure portal and check if Microsoft.Bing is registered?
Go to Subscriptions > Select Your Subscription > Resource Providers > Search for Microsoft.Bing
If not registered, could you please select the resource provider and select Register and then check if the pricing drop down is enabled?
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