The Value does not match regex condition will let you restrict an Event based on a connected Event data. You will have to specify two parameters in order for the condition to work.

First parameter is the connected Event data Value where the second parameter, a regular expression, should not be found.

By selecting Page URL as Value and "[0-9]" in Does not match regex will restrict the Event to only trigger when any of the characters 0 to 9 are not found in the current URL.

Note that this condition must always be wired to an Event data before you can select it as a parameter.

Further reading:

Creating your first events