Cannot purchase and Pro 50 000 nearly exhausted!

Describe the problem/error/question

What is the error message (if any)?

Our 50000 executions are nearly completely used-up. At 80% we got a notification that we can purchase additional executions. Your AI Assistant Nate N. outlined a step by step instruction how to do that. The problem is that this steps are not working. When I choose for the Pro plan the “Custom” tier the button below greys out and I cannot proceed.

We urgently need to get at least 12000 additional executions until the end of the month (3 full days)!

Please help! The cloud account is lecturio.app.n8n.cloud.