The following are possible reasons why you may not be able to purchase a Gold Pass.
Note: Please review the below even if a message that reads "Already purchased on another device, or purchases restricted by OS settings." displays when you try to make the purchase.
1. You have already purchased a Gold Pass.
Only one Gold Pass may be purchased per Apple ID per save data. If multiple family members are using the same Apple ID and one of them has already purchased a Gold Pass, other family members will not be able to purchase a Gold Pass. In this situation, another Apple ID would need to be used.
If a Gold Pass has been canceled but has not expired yet, a new Gold Pass cannot be purchased until that pass has expired.
2. Purchasing is restricted.
If credit card usage is restricted or parental controls that restrict making purchases have been implemented, then a purchase cannot be made.
Please check that there are no problems with the payment method.
3. The remaining balance is insufficient.
Please try purchasing again after preparing your balance.
Note that "insufficient funds" may display even when subscribing to the free trial.
Since this is a setting on App Store side, please contact the store if this is displayed when subscribing to the free trial.