How to create measure counting unique number of delivery customer numbers?

[Power_BI_Adapt]

Dear All,

I am looking for a possibility to calculate the unique number of delivery customer numbers from a customer base. Simplified it does show the following situation:

How do I write the measure to come to the above result?

Thanks in advance!

Kind regards

[Ahmedx · Accepted solution]

plse try this
measure= COUNTROWS('table')