I saw this in a Jose Cuervo Black Medallion television advertisement.

Problem:
There is no verb in this (non-)sentence.

Explanation:
The word “walkup” is a noun and means an above-ground-floor apartment home or office with no elevator.

The writer of the television advertisement should have used the verb phrase “walk up” instead of the noun “walkup”.

The verb phrase “walk up” in the context of what was intended by the writer means go.

In other words, “walkup” and “walk up” are not synonyms!

Solution:
“Step 1. Walk up to the bar.”