Patreon does not enable charge upfront upon request and cannot give you an ETA on when it will be available for you.
The feature is still in beta and not available to brand new creators.
When it's available for you as an active creator with patrons it will appear in your settings. We recommend checking your settings on the 1st of each month to see if it has been enabled for you.
If it does not appear in your settings, it is not currently available for you at this time.