Vodafone App - Top Up - Don't understand

We have an old device, but it has the Vodafone App.

The phone is on pre-pay.

The app says: Balance $13.19 (The pre-pay plan is $15.00 per month)

But has an asterisk i.e. 'Please top up to renew your plan'

At the bottom of the app it says 'CREDIT EXPIRES 05 APR' - Cannot see any Year. I don't know how I can see it.

So what is the app telling me.

Do I need to top up immediately?

If so, how do I know when it expired or in the future when it will expire?

Perhaps, the phone is too small to show all the information. I think it is 4 inch.