Blaze payment plan, pay using fixed amount on credit card

[Matt Harris]

I am currently getting the following warning when I try invoking functions in firebase:

quota exceeded (Quota exceeded for quota group 'CPUMilliSecondsDailyNonbillable' and limit 'CLIENT_PROJECT-1d' of service 'cloudfunctions.googleapis.com' for consumer 'project_number:388436954224'., Quota exceeded for quota group 'CPUMilliSecondsNonbillable' and limit 'CLIENT_PROJECT-1d' of service 'cloudfunctions.googleapis.com' for consumer 'project_number:388436954224'.); to increase quotas, enable billing in your project at https://console.cloud.google.com/billing?project=pushmessage-bd1eb. Function cannot be executed.

I have noticed I need to use the Blaze pay-as-you-go plan. However, I cannot get a variable monthly amount approved on our credit card - is there a way I can pay a fixed amount?