Tap "See all" on Home screen and find the declined transaction. Selecting it will display the transaction details explaining the reason and advise on what to do to make the next transaction successful.
The most common reasons for declined payments are:
You also won’t be able to withdraw any amount in the following countries, as they are currently subject to international sanctions:
As well as the following cities in the Crimean region:
If you still have any more questions about your declined withdrawal, feel free to submit a support request here.