AdBlue Topup

[cosmarchy]

Hi,

I received a warning to top up the AdBlue in my car. The message says there is 1400 mile range left and provides min 5l and max 13l topup.

It's the first time since owning by car so am a little unsure of the significance of the min and max limits. I've done some research and see there is a pump near me. It appears the pump acts as any other filling pump and cuts out when the fill limit is reached. If that is indeed the case why is there an upper limit of 13l? The pump wont know and fill until it's complete...
Or am I supposed to measure it out somehow to ensure I put no more than 13l?

It ways that overfilling can cause damage but I cannot see how that is possible using a pump given it cuts out and if filling from a container, you'd get rather damp if you keep going once you reach the top and presumably you'd still have to measure 13l?

What is the "correct" procedure for this.

Thanks