Salam alaykom mawlana, how are you.
Mawlana I want to work and I live in the west. I want to work in the supermarkt as a cashier. But sometimes someone buys alcohol. Can I work at a place were alcohol is sold and can I sell it to a customer for the supermarket?

Walaikumussalam brother
Alhumdulillah I'm doing well
Praying for you best health and prosperous life.
You are not allowed to sell alcohol.Either try to find work where alcohol is not involved or find any other position in supermarket where you will not be involved in this.
Inshallah you will be able to find rizqe halal and pure as quran said
Whoever is careful of his duty to Allah , Allah will open the new outlets and grant him sustenance from the place he never think.
(Sura Talaq ayah 2,3 )