When you are logged in, click on your profile photo in the top right corner. Then open “Subscriptions” > “Change billing information” > "Edit Subscription" > “Update Payment Method”.
After you click on your profile photo, from the drop-down menu choose the organization you'd like to update the payment details for. On the left side of your organization page open "Subscription" > "Update payment method". You’ll be redirected to the Semaphore CI Store where you’ll be able to see the subscription details. Afterwards, click on "Edit subscription" > "Update Payment Method".
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